diff --git a/__tests__/__snapshots__/index.js.snap b/__tests__/__snapshots__/index.js.snap
index 53d2317a..bf72ddb8 100644
--- a/__tests__/__snapshots__/index.js.snap
+++ b/__tests__/__snapshots__/index.js.snap
@@ -377,6 +377,16 @@ Object {
       "DEVELOP": "Development",
       "QA": "Quality Assurance",
     },
+    "OLD_COMPETITION_TRACKS": Object {
+      "DATA_SCIENCE": "DATA_SCIENCE",
+      "DESIGN": "DESIGN",
+      "DEVELOP": "DEVELOP",
+      "QA": "QA",
+    },
+    "OLD_SUBTRACKS": Object {
+      "BUG_HUNT": "BUG_HUNT",
+      "TEST_SUITES": "TEST_SUITES",
+    },
     "REVIEW_OPPORTUNITY_TYPES": Object {
       "Contest Review": "Review",
       "Iterative Review": "Iterative Review",
diff --git a/package.json b/package.json
index 35c82bc4..8086c298 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
     "lint:js": "./node_modules/.bin/eslint --ext .js,.jsx .",
     "test": "npm run lint && npm run jest"
   },
-  "version": "1000.19.51",
+  "version": "1000.20.3",
   "dependencies": {
     "auth0-js": "^6.8.4",
     "config": "^3.2.0",
diff --git a/src/services/challenges.js b/src/services/challenges.js
index fd0fecec..5f497304 100644
--- a/src/services/challenges.js
+++ b/src/services/challenges.js
@@ -328,7 +328,7 @@ class ChallengesService {
     if (/^[\d]{5,8}$/.test(challengeId)) {
       isLegacyChallenge = true;
       challenge = await this.private.getChallenges('/challenges/', { legacyId: challengeId })
-        .then(res => res.challenges[0]);
+        .then(res => res.challenges);
     } else {
       challenge = await this.private.getChallenges(`/challenges/${challengeId}`)
         .then(res => res.challenges);
diff --git a/src/services/reviewOpportunities.js b/src/services/reviewOpportunities.js
index 51af9e44..87f8dcd3 100644
--- a/src/services/reviewOpportunities.js
+++ b/src/services/reviewOpportunities.js
@@ -4,23 +4,37 @@
  * submitting applications.
  */
 import _ from 'lodash';
+import { COMPETITION_TRACKS, OLD_COMPETITION_TRACKS, OLD_SUBTRACKS } from 'utils/tc';
 import { getApi } from './api';
 
 /**
  * Sync the fields of V3 and V5 for front-end to process successfully
- * @param challenges - challenges to normalize
+ * @param opportunities - opportunities to normalize
  */
-export function normalizeChallenges(challenges) {
-  if (challenges) {
-    _.map(challenges, (ch) => {
-      const { challenge } = ch;
-      if (challenge.technologies && challenge.technologies.includes('Data Science')) {
-        challenge.track = 'DATA_SCIENCE';
+export function normalizeChallenges(opportunities) {
+  if (opportunities) {
+    /* Issue#4739 : Temporary add track to review opportunities challenges
+     * until receive API V5 update. */
+    _.map(opportunities, (opportunity) => {
+      const { challenge } = opportunity;
+      challenge.track = COMPETITION_TRACKS.DEVELOP;
+      if (challenge.technologies) {
+        if (challenge.technologies.includes(COMPETITION_TRACKS.DATA_SCIENCE)) {
+          challenge.track = COMPETITION_TRACKS.DATA_SCIENCE;
+        } else if (challenge.technologies.includes(OLD_COMPETITION_TRACKS.QA)) {
+          challenge.track = COMPETITION_TRACKS.QA;
+        }
+      } else if (challenge.subTrack === OLD_SUBTRACKS.TEST_SUITES
+          || challenge.subTrack === OLD_SUBTRACKS.BUG_HUNT) {
+        challenge.track = COMPETITION_TRACKS.QA;
+      } else if (challenge.track === OLD_COMPETITION_TRACKS.DESIGN) {
+        challenge.track = COMPETITION_TRACKS.DESIGN;
       }
-      return _.defaults(ch, { challenge });
+      return _.defaults(opportunity, { challenge });
     });
   }
-  return challenges;
+
+  return opportunities;
 }
 
 /**
diff --git a/src/utils/challenge/filter.js b/src/utils/challenge/filter.js
index 263c3132..549a36c3 100644
--- a/src/utils/challenge/filter.js
+++ b/src/utils/challenge/filter.js
@@ -71,8 +71,9 @@ import { COMPETITION_TRACKS, REVIEW_OPPORTUNITY_TYPES } from '../tc';
  */
 
 function filterByGroupIds(challenge, state) {
-  if (!state.groupIds) return true;
-  return state.groupIds.some(id => challenge.groups[id]);
+  if (_.isEmpty(state.groupIds)) return true;
+  if (_.isEmpty(challenge.groups)) return false;
+  return state.groupIds.some(id => challenge.groups.find(gId => gId === id));
 }
 
 function filterByRegistrationOpen(challenge, state) {
@@ -144,12 +145,18 @@ function filterByStatus(challenge, state) {
 }
 
 function filterByTags(challenge, state) {
-  if (!state.tags) return true;
+  if (_.isEmpty(state.tags)) return true;
   const { platforms, tags } = challenge;
   const str = `${platforms} ${tags}`.toLowerCase();
   return state.tags.some(tag => str.includes(tag.toLowerCase()));
 }
 
+function filterByEvents(challenge, state) {
+  if (_.isEmpty(state.events)) return true;
+  if (_.isEmpty(challenge.events)) return false;
+  return state.events.some(key => challenge.events.find(e => e.key === key));
+}
+
 function filterByText(challenge, state) {
   if (!state.text) return true;
   const str = `${challenge.name} ${challenge.tags} ${challenge.platforms} ${challenge.tags}`
@@ -173,8 +180,11 @@ function filterByUpcoming(challenge, state) {
 }
 
 function filterByUsers(challenge, state) {
-  if (!state.userChallenges) return true;
-  return state.userChallenges.find(ch => challenge.id === ch);
+  const userId = _.get(state, 'userId', null);
+  if (userId) {
+    return _.get(challenge, ['users', userId], false);
+  }
+  return true;
 }
 
 /**
@@ -214,6 +224,7 @@ export function getFilterFunction(state) {
       && filterByGroupIds(challenge, state)
       && filterByText(challenge, state)
       && filterByTags(challenge, state)
+      && filterByEvents(challenge, state)
       && filterByTypes(challenge, state)
       && filterByUsers(challenge, state)
       && filterByEndDate(challenge, state)
@@ -343,7 +354,7 @@ export function combine(...filters) {
   const res = {};
   filters.forEach((filter) => {
     combineEndDate(res, filter);
-    combineArrayRules(res, filter, 'groups');
+    combineArrayRules(res, filter, 'groupIds');
     /* TODO: The registrationOpen rule is just ignored for now. */
     combineStartDate(res, filter);
     combineArrayRules(res, filter, 'or', true);
@@ -380,7 +391,7 @@ export function combine(...filters) {
  */
 export function mapToBackend(filter) {
   const res = {};
-  if (filter.groups) res.groups = filter.groups;
+  if (filter.groupIds) res.groups = filter.groupIds;
   return res;
 }
 
diff --git a/src/utils/tc.js b/src/utils/tc.js
index 5388d4bb..28bcf3b2 100644
--- a/src/utils/tc.js
+++ b/src/utils/tc.js
@@ -17,6 +17,18 @@ export const COMPETITION_TRACKS = {
   QA: 'Quality Assurance',
 };
 
+export const OLD_COMPETITION_TRACKS = {
+  DATA_SCIENCE: 'DATA_SCIENCE',
+  DESIGN: 'DESIGN',
+  DEVELOP: 'DEVELOP',
+  QA: 'QA',
+};
+
+export const OLD_SUBTRACKS = {
+  TEST_SUITES: 'TEST_SUITES',
+  BUG_HUNT: 'BUG_HUNT',
+};
+
 /**
  * Review Opportunity types
  */