JSFiddle - React, Tailwind, and code Playground

JavaScript

var tst = 
[
 {"topicId":1,"subTopicId":1,"topicName":"a","subTopicName1":"w"},
 {"topicId":2,"subTopicId":2,"topicName":"b","subTopicName2":"x"},
 {"topicId":3,"subTopicId":3,"topicName":"c","subTopicName3":"y"},
 {"topicId":4,"subTopicId":4,"topicName":"c","subTopicName4":"z"}
];

var t = _.uniq(tst, 'topicId'),
    t2 = _.uniq(t, 'topicName'),
    dataMap = {
        topicId: 'id',
        topicName: 'name'
    };


var finalT = t2.map(function (topic) {
    var t = {};
    for (var key in dataMap) {
        t[dataMap[key]] = topic[key];
    };
    return t;
});

console.log(finalT);