diff --git a/src/discussions/posts/PostsView.test.jsx b/src/discussions/posts/PostsView.test.jsx
index f7520ebb..accddcc4 100644
--- a/src/discussions/posts/PostsView.test.jsx
+++ b/src/discussions/posts/PostsView.test.jsx
@@ -15,11 +15,13 @@ import { AppProvider } from '@edx/frontend-platform/react';
 
 import { Routes, ThreadType } from '../../data/constants';
 import { initializeStore } from '../../store';
+import { getCohortsApiUrl } from '../cohorts/data/api';
 import { DiscussionContext } from '../common/context';
 import { threadsApiUrl } from './data/api';
 import { PostsView } from './index';
 
 import './data/__factories__';
+import '../cohorts/data/__factories__';
 
 const courseId = 'course-v1:edX+TestX+Test_Course';
 let store;
@@ -89,6 +91,7 @@ describe('PostsView', () => {
     });
     Factory.resetAll();
     axiosMock = new MockAdapter(getAuthenticatedHttpClient());
+    axiosMock.onGet(getCohortsApiUrl(courseId)).reply(200, Factory.buildList('cohort', 1));
     axiosMock.onGet(threadsApiUrl)
       .reply((args) => {
         const threadAttrs = {};
@@ -152,11 +155,25 @@ describe('PostsView', () => {
         fireEvent.click(dropDownButton);
       });
     });
+
     test('test that the filter bar works', async () => {
       // 3 type filters: all, discussion, question
       // 5 status filters: any, unread, following, reported, unanswered
       // 3 sort: activity, comments, likes
-      expect(screen.queryAllByRole('radio')).toHaveLength(11);
+      // 2 cohort: all groups, 1 api mock response cohort
+      expect(screen.queryAllByRole('radio')).toHaveLength(13);
+    });
+
+    test('test that the cohorts filter works', async () => {
+      await act(async () => {
+        fireEvent.click(screen.getByLabelText('Cohort 1'));
+      });
+
+      dropDownButton = screen.getByRole('button', {
+        name: /All posts in Cohort 1 by recent activity/i,
+      });
+
+      expect(dropDownButton).toBeInTheDocument();
     });
 
     describe.each([
@@ -192,6 +209,14 @@ describe('PostsView', () => {
         label: 'Most likes',
         queryParam: { order_by: 'vote_count' },
       },
+      {
+        label: 'All groups',
+        queryParam: { group_id: undefined },
+      },
+      {
+        label: 'Cohort 1',
+        queryParam: { group_id: 'cohort-1' },
+      },
     ])(
       'one at a time',
       ({
diff --git a/src/discussions/posts/data/api.js b/src/discussions/posts/data/api.js
index 196b3821..be4a5d5b 100644
--- a/src/discussions/posts/data/api.js
+++ b/src/discussions/posts/data/api.js
@@ -42,6 +42,7 @@ export async function getThreads(
     flagged,
     threadType,
     countFlagged,
+    cohort,
   } = {},
 ) {
   const params = snakeCaseObject({
@@ -58,6 +59,7 @@ export async function getThreads(
     author,
     flagged,
     countFlagged,
+    groupId: cohort,
   });
   const { data } = await getAuthenticatedHttpClient().get(threadsApiUrl, { params });
   return data;
diff --git a/src/discussions/posts/data/slices.js b/src/discussions/posts/data/slices.js
index 1cdf389a..a3248fb9 100644
--- a/src/discussions/posts/data/slices.js
+++ b/src/discussions/posts/data/slices.js
@@ -31,6 +31,7 @@ const threadsSlice = createSlice({
     filters: {
       status: PostsStatusFilter.ALL,
       postType: ThreadType.ALL,
+      cohort: '',
       search: '',
     },
     postEditorVisible: false,
@@ -146,6 +147,10 @@ const threadsSlice = createSlice({
       state.filters.postType = payload;
       state.pages = [];
     },
+    setCohortFilter: (state, { payload }) => {
+      state.filters.cohort = payload;
+      state.pages = [];
+    },
     setSearchQuery: (state, { payload }) => {
       state.filters.search = payload;
       // Search doesn't work with following
@@ -190,6 +195,7 @@ export const {
   updateThreadAsRead,
   updateThreadSuccess,
   setPostsTypeFilter,
+  setCohortFilter,
   setSortedBy,
   setStatusFilter,
   setSearchQuery,
diff --git a/src/discussions/posts/data/thunks.js b/src/discussions/posts/data/thunks.js
index e198e009..ba8412eb 100644
--- a/src/discussions/posts/data/thunks.js
+++ b/src/discussions/posts/data/thunks.js
@@ -122,6 +122,9 @@ export function fetchThreads(courseId, {
   if (filters.search) {
     options.textSearch = filters.search;
   }
+  if (filters.cohort) {
+    options.cohort = filters.cohort;
+  }
   return async (dispatch) => {
     try {
       dispatch(fetchThreadsRequest({ courseId }));
diff --git a/src/discussions/posts/post-editor/PostEditor.jsx b/src/discussions/posts/post-editor/PostEditor.jsx
index 8606cba8..211d5014 100644
--- a/src/discussions/posts/post-editor/PostEditor.jsx
+++ b/src/discussions/posts/post-editor/PostEditor.jsx
@@ -161,7 +161,7 @@ function PostEditor({
   };
 
   useEffect(() => {
-    if (userIsPrivileged) {
+    if (userIsPrivileged && isEmpty(cohorts)) {
       dispatch(fetchCourseCohorts(courseId));
     }
     if (editExisting) {
diff --git a/src/discussions/posts/post-editor/PostEditor.test.jsx b/src/discussions/posts/post-editor/PostEditor.test.jsx
index 4d080a7e..bc997171 100644
--- a/src/discussions/posts/post-editor/PostEditor.test.jsx
+++ b/src/discussions/posts/post-editor/PostEditor.test.jsx
@@ -137,7 +137,7 @@ describe('PostEditor', () => {
     );
   });
 
-  describe('chorting', () => {
+  describe('cohorting', () => {
     const dividedncw = ['ncw-topic-2'];
     const dividedcw = ['category-1-topic-2', 'category-2-topic-1', 'category-2-topic-2'];
 
diff --git a/src/discussions/posts/post-filter-bar/PostFilterBar.jsx b/src/discussions/posts/post-filter-bar/PostFilterBar.jsx
index 174f0c1f..d33ef9e0 100644
--- a/src/discussions/posts/post-filter-bar/PostFilterBar.jsx
+++ b/src/discussions/posts/post-filter-bar/PostFilterBar.jsx
@@ -1,18 +1,27 @@
-import React, { useState } from 'react';
+import React, { useEffect, useMemo, useState } from 'react';
 import PropTypes from 'prop-types';
 
 import classNames from 'classnames';
+import { capitalize, isEmpty, toString } from 'lodash';
 import { useDispatch, useSelector } from 'react-redux';
+import { useParams } from 'react-router-dom';
 
 import { injectIntl, intlShape } from '@edx/frontend-platform/i18n';
-import { Collapsible, Form, Icon } from '@edx/paragon';
-import { Check, Sort } from '@edx/paragon/icons';
+import {
+  Collapsible, Form, Icon, Spinner,
+} from '@edx/paragon';
+import { Check, Tune } from '@edx/paragon/icons';
 
 import {
-  PostsStatusFilter, ThreadOrdering, ThreadType,
+  PostsStatusFilter, RequestStatus,
+  ThreadOrdering, ThreadType,
 } from '../../../data/constants';
+import { selectCourseCohorts } from '../../cohorts/data/selectors';
+import { fetchCourseCohorts } from '../../cohorts/data/thunks';
 import { selectUserIsPrivileged } from '../../data/selectors';
-import { setPostsTypeFilter, setSortedBy, setStatusFilter } from '../data';
+import {
+  setCohortFilter, setPostsTypeFilter, setSortedBy, setStatusFilter,
+} from '../data';
 import { selectThreadFilters, selectThreadSorting } from '../data/selectors';
 import messages from './messages';
 
@@ -22,12 +31,16 @@ const ActionItem = ({
   value,
   selected,
 }) => (
-  <label htmlFor={id} className="focus border-bottom-0 d-flex p-1 m-2 align-items-center" data-testid={value === selected ? 'selected' : null}>
+  <label
+    htmlFor={id}
+    className="focus border-bottom-0 d-flex align-items-center w-100 py-2 m-0 font-weight-500"
+    data-testid={value === selected ? 'selected' : null}
+  >
     <Icon src={Check} className={classNames('text-success mr-2', { invisible: value !== selected })} />
     <Form.Radio id={id} className="sr-only sr-only-focusable" value={value} tabIndex={0}>
       {label}
     </Form.Radio>
-    <span aria-hidden>
+    <span aria-hidden className="text-truncate">
       {label}
     </span>
   </label>
@@ -45,11 +58,18 @@ function PostFilterBar({
   intl,
 }) {
   const dispatch = useDispatch();
+  const { courseId } = useParams();
   const userIsPrivileged = useSelector(selectUserIsPrivileged);
   const currentSorting = useSelector(selectThreadSorting());
   const currentFilters = useSelector(selectThreadFilters());
+  const { status } = useSelector(state => state.cohorts);
+  const cohorts = useSelector(selectCourseCohorts);
   const [isOpen, setOpen] = useState(false);
 
+  const selectedCohort = useMemo(() => cohorts.find(cohort => (
+    toString(cohort.id) === currentFilters.cohort)),
+  [currentFilters.cohort]);
+
   const handleSortFilterChange = (event) => {
     const currentType = currentFilters.postType;
     const currentStatus = currentFilters.status;
@@ -76,115 +96,173 @@ function PostFilterBar({
     if (name === 'sort') {
       dispatch(setSortedBy(value));
     }
+    if (name === 'cohort') {
+      dispatch(setCohortFilter(value));
+    }
     setOpen(false);
   };
+
+  useEffect(() => {
+    if (userIsPrivileged && isEmpty(cohorts)) {
+      dispatch(fetchCourseCohorts(courseId));
+    }
+  }, [courseId, userIsPrivileged]);
+
   return (
-    <Collapsible
-      styling="card-lg"
-      iconWhenOpen={<Icon src={Sort} />}
-      iconWhenClosed={<Icon src={Sort} />}
-      title={intl.formatMessage(messages.sortFilterStatus, {
-        own: filterSelfPosts,
-        type: currentFilters.postType,
-        sort: currentSorting,
-        status: currentFilters.status,
-      })}
+    <Collapsible.Advanced
       open={isOpen}
-      onToggle={setOpen}
+      onToggle={() => setOpen(!isOpen)}
+      className="collapsible-card-lg border-right-0"
     >
-      <Form className="d-flex flex-row p-1 justify-content-between">
-        <Form.RadioSet
-          name="type"
-          className="d-flex flex-column list-group list-group-flush"
-          value={currentFilters.postType}
-          onChange={handleSortFilterChange}
-        >
-          <ActionItem
-            id="type-all"
-            label={intl.formatMessage(messages.allPosts)}
-            value={ThreadType.ALL}
-            selected={currentFilters.postType}
-          />
-          <ActionItem
-            id="type-discussions"
-            label={intl.formatMessage(messages.filterDiscussions)}
-            value={ThreadType.DISCUSSION}
-            selected={currentFilters.postType}
-          />
-          <ActionItem
-            id="type-questions"
-            label={intl.formatMessage(messages.filterQuestions)}
-            value={ThreadType.QUESTION}
-            selected={currentFilters.postType}
-          />
-        </Form.RadioSet>
-        <Form.RadioSet
-          name="status"
-          className="d-flex flex-column list-group list-group-flush"
-          value={currentFilters.status}
-          onChange={handleSortFilterChange}
-        >
-          <ActionItem
-            id="status-any"
-            label={intl.formatMessage(messages.filterAnyStatus)}
-            value={PostsStatusFilter.ALL}
-            selected={currentFilters.status}
-          />
-          <ActionItem
-            id="status-unread"
-            label={intl.formatMessage(messages.filterUnread)}
-            value={PostsStatusFilter.UNREAD}
-            selected={currentFilters.status}
-          />
-          <ActionItem
-            id="status-following"
-            label={intl.formatMessage(messages.filterFollowing)}
-            value={PostsStatusFilter.FOLLOWING}
-            selected={currentFilters.status}
-          />
-          {userIsPrivileged
-          && (
-          <ActionItem
-            id="status-reported"
-            label={intl.formatMessage(messages.filterReported)}
-            value={PostsStatusFilter.REPORTED}
-            selected={currentFilters.status}
-          />
+      <Collapsible.Trigger className="collapsible-trigger border-0">
+        <span className="text-primary-700 pr-4">
+          {intl.formatMessage(messages.sortFilterStatus, {
+            own: filterSelfPosts,
+            type: currentFilters.postType,
+            sort: currentSorting,
+            status: currentFilters.status,
+            cohortType: selectedCohort?.name ? 'group' : 'all',
+            cohort: capitalize(selectedCohort?.name),
+          })}
+        </span>
+        <Collapsible.Visible whenClosed>
+          <Icon src={Tune} />
+        </Collapsible.Visible>
+        <Collapsible.Visible whenOpen>
+          <Icon src={Tune} />
+        </Collapsible.Visible>
+      </Collapsible.Trigger>
+      <Collapsible.Body className="collapsible-body px-4 pb-3 pt-0">
+        <Form>
+          <div className="d-flex flex-row py-2 justify-content-between">
+            <Form.RadioSet
+              name="type"
+              className="d-flex flex-column list-group list-group-flush"
+              value={currentFilters.postType}
+              onChange={handleSortFilterChange}
+            >
+              <ActionItem
+                id="type-all"
+                label={intl.formatMessage(messages.allPosts)}
+                value={ThreadType.ALL}
+                selected={currentFilters.postType}
+              />
+              <ActionItem
+                id="type-discussions"
+                label={intl.formatMessage(messages.filterDiscussions)}
+                value={ThreadType.DISCUSSION}
+                selected={currentFilters.postType}
+              />
+              <ActionItem
+                id="type-questions"
+                label={intl.formatMessage(messages.filterQuestions)}
+                value={ThreadType.QUESTION}
+                selected={currentFilters.postType}
+              />
+            </Form.RadioSet>
+            <Form.RadioSet
+              name="status"
+              className="d-flex flex-column list-group list-group-flush"
+              value={currentFilters.status}
+              onChange={handleSortFilterChange}
+            >
+              <ActionItem
+                id="status-any"
+                label={intl.formatMessage(messages.filterAnyStatus)}
+                value={PostsStatusFilter.ALL}
+                selected={currentFilters.status}
+              />
+              <ActionItem
+                id="status-unread"
+                label={intl.formatMessage(messages.filterUnread)}
+                value={PostsStatusFilter.UNREAD}
+                selected={currentFilters.status}
+              />
+              <ActionItem
+                id="status-following"
+                label={intl.formatMessage(messages.filterFollowing)}
+                value={PostsStatusFilter.FOLLOWING}
+                selected={currentFilters.status}
+              />
+              {userIsPrivileged && (
+                <ActionItem
+                  id="status-reported"
+                  label={intl.formatMessage(messages.filterReported)}
+                  value={PostsStatusFilter.REPORTED}
+                  selected={currentFilters.status}
+                />
+              )}
+              <ActionItem
+                id="status-unanswered"
+                label={intl.formatMessage(messages.filterUnanswered)}
+                value={PostsStatusFilter.UNANSWERED}
+                selected={currentFilters.status}
+              />
+            </Form.RadioSet>
+            <Form.RadioSet
+              name="sort"
+              className="d-flex flex-column list-group list-group-flush"
+              value={currentSorting}
+              onChange={handleSortFilterChange}
+            >
+              <ActionItem
+                id="sort-activity"
+                label={intl.formatMessage(messages.lastActivityAt)}
+                value={ThreadOrdering.BY_LAST_ACTIVITY}
+                selected={currentSorting}
+              />
+              <ActionItem
+                id="sort-comments"
+                label={intl.formatMessage(messages.commentCount)}
+                value={ThreadOrdering.BY_COMMENT_COUNT}
+                selected={currentSorting}
+              />
+              <ActionItem
+                id="sort-votes"
+                label={intl.formatMessage(messages.voteCount)}
+                value={ThreadOrdering.BY_VOTE_COUNT}
+                selected={currentSorting}
+              />
+            </Form.RadioSet>
+          </div>
+          {userIsPrivileged && (
+            <>
+              <div className="border-bottom my-2" />
+              {status === RequestStatus.IN_PROGRESS ? (
+                <div className="d-flex justify-content-center p-4">
+                  <Spinner animation="border" variant="primary" size="lg" />
+                </div>
+              ) : (
+                <div className="d-flex flex-row pt-2">
+                  <Form.RadioSet
+                    name="cohort"
+                    className="d-flex flex-column list-group list-group-flush w-100"
+                    value={currentFilters.cohort}
+                    onChange={handleSortFilterChange}
+                  >
+                    <ActionItem
+                      id="all-groups"
+                      label="All groups"
+                      value=""
+                      selected={currentFilters.cohort}
+                    />
+                    {cohorts.map(cohort => (
+                      <ActionItem
+                        key={cohort.id}
+                        id={cohort.id}
+                        label={capitalize(cohort.name)}
+                        value={toString(cohort.id)}
+                        selected={currentFilters.cohort}
+                      />
+                    ))}
+                  </Form.RadioSet>
+                </div>
+              )}
+            </>
           )}
-          <ActionItem
-            id="status-unanswered"
-            label={intl.formatMessage(messages.filterUnanswered)}
-            value={PostsStatusFilter.UNANSWERED}
-            selected={currentFilters.status}
-          />
-        </Form.RadioSet>
-        <Form.RadioSet
-          name="sort"
-          className="d-flex flex-column list-group list-group-flush"
-          value={currentSorting}
-          onChange={handleSortFilterChange}
-        >
-          <ActionItem
-            id="sort-activity"
-            label={intl.formatMessage(messages.lastActivityAt)}
-            value={ThreadOrdering.BY_LAST_ACTIVITY}
-            selected={currentSorting}
-          />
-          <ActionItem
-            id="sort-comments"
-            label={intl.formatMessage(messages.commentCount)}
-            value={ThreadOrdering.BY_COMMENT_COUNT}
-            selected={currentSorting}
-          />
-          <ActionItem
-            id="sort-votes"
-            label={intl.formatMessage(messages.voteCount)}
-            value={ThreadOrdering.BY_VOTE_COUNT}
-            selected={currentSorting}
-          />
-        </Form.RadioSet>
-      </Form>
-    </Collapsible>
+        </Form>
+      </Collapsible.Body>
+    </Collapsible.Advanced>
   );
 }
 
diff --git a/src/discussions/posts/post-filter-bar/messages.js b/src/discussions/posts/post-filter-bar/messages.js
index 27dc13de..0024e874 100644
--- a/src/discussions/posts/post-filter-bar/messages.js
+++ b/src/discussions/posts/post-filter-bar/messages.js
@@ -83,8 +83,8 @@ const messages = defineMessages({
   },
   sortFilterStatus: {
     id: 'discussions.posts.sort-filter.sortFilterStatus',
-    defaultMessage: `{own, select, 
-      false {All} 
+    defaultMessage: `{own, select,
+      false {All}
       true {Own}
     } {status, select,
       statusAll {}
@@ -92,15 +92,18 @@ const messages = defineMessages({
       statusFollowing {followed}
       statusReported {reported}
       statusUnanswered {unanswered}
-    } {type, select,  
-      discussion {discussions} 
+    } {type, select,
+      discussion {discussions}
       question {questions}
       all {posts}
-     } by {sort, select,
-        lastActivityAt {recent activity}
-        commentCount {most activity}
-        voteCount {most votes}
-     }`,
+    } {cohortType, select,
+        all {}
+        group {in {cohort}}
+    } by {sort, select,
+      lastActivityAt {recent activity}
+      commentCount {most activity}
+      voteCount {most votes}
+    }`,
     description: 'Status message showing current sorting and filtering status',
   },
 });