Elasticsearch, MongoDb, Mongoosastic querying array of objects

Question

I am trying to index only the 'particulars' field of boqEntry into an Elasticsearch instance using Mongoosastic and later query them. 'boqList' inside BOQ comprises of boqEntries. I have defined my schema as described in the code below. I am indexing my BOQ document after uploading them via FilePond. Whenever I perform the query (http://localhost:9200/boqss/boqs/_search) onto Elasticsearch.

I get a response like this :

 "hits": [
            {
                "_index": "boqss",
                "_type": "boqs",
                "_id": "5d9730d83f756d04a8d6dbfe",
                "_score": 1.0,
                "_source": {
                    "projectId": "5d860711cf3b052a34a84f6c",
                    "boqList": [
                        {
                            "particulars": "Excavation "
                        },
                        {
                            "particulars": "Providing & laying Rubble Soling"
                        },
                        {
                            "particulars": "Providing & laying PCC M10"
                        },
                        {
                            "particulars": "Providing & Laying Reinforcement With Cutting, Bending & Binding With Binding Wire Etc Complete."
                        },
                        {
                            "particulars": "Providing & Making Double Scaffolding"
                        },
                        {
                            "particulars": "Providing & Casting R.C.C M25"
                        },
                        {
                            "particulars": "Providing & Applying Cement Plaster"
                        },

...

However I want to be able to retrieve only those specific 'particulars' from the boqList array that match a searchTerm from my search box that I am implementing in my React based front-end, like a full text search. I am relatively new to the MERN stack, Mongoose and Elasticsearch. I would really appreciate any help. Thank you !!

Here is the mongoose schema :

const mongoose = require('mongoose')
const Schema = mongoose.Schema

var mongoosastic  = require('mongoosastic')


const boqEntry = new Schema({ 
            particulars : {type : String, es_indexed : true},
            quantity : {type : Number},
            unit : {type : String},
            rate : {type : Number}, 
            amount : {type : Number}, 
        });

const BOQ = new Schema(
    {

        projectId : { type : String},
        boqList  : {type : [boqEntry], es_type : 'nested'}


     },
    { timestamps: true },
);

BOQ.plugin(mongoosastic)


module.exports = mongoose.model('boqs', BOQ)