JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/3.10.1/lodash.min.js"></script>

JavaScript

var currentfilters = [{
        "id": "topics",
        "name": "Topics",
        "filters": [{
            "id": "isSubTopic",
            "label": "isSubTopic",
            "search": "isSubTopic",
            "num": 15
        }]
    }, {
        "id": "isSubTopic",
        "name": "isSubTopic",
        "parentSearch": "Topics",
        "filters": [{
            "id": "subtopicFilter",
            "label": "subtopicFilter",
            "search": "subtopicFilter",
            "num": 2
        }, {
            "id": "subtopicFilter1",
            "label": "subtopicFilter1",
            "search": "subtopicFilter1",
            "num": 2
        }]
    }, {
        "id": "notSubTopic",
        "name": "notSubTopic",
        "parentSearch": "uniueParentSearch",
        "filters": [{
            "id": "notSubTopic1",
            "label": "notSubTopic1",
            "search": "notSubTopic1",
            "num": 5
        }]
    }
];




function checkIfSubtopic(memo, value, key) {
	if(value.parentSearch) {
    //check if value.parentSearch is in any of the value.filters
    console.log("find?", _.find(currentfilters, value.parentSearch));
  	if(_.find(currentfilters, value.parentSearch)){
    		console.log("is subtopic?");
    } else {
    	console.log("not sub topic");
    }
  }
  return memo.concat(memo[key] = value);

}


console.log(_.reduce(currentfilters, checkIfSubtopic, {}));