JSFiddle - React, Tailwind, and code Playground

JavaScript

var b = {
"SearchWithMasterDataDIdAndScandefinitionDAO": [
    {
        "dateDm_id": 20120602,
        "issueValue": "ELTDIWKZ",
        "scanName": "Company Stored as Person (Given Name)",
        "severityCode": 1,
        "severityName": "High",
        "totalDiscovered": 1
    },
    {
        "dateDm_id": 20120602,
        "issueValue": "LTDFPVOI",
        "scanName": "Company Stored as Person (Given Name)",
        "severityCode": 1,
        "severityName": "High",
        "totalDiscovered": 1
    },
    {
        "dateDm_id": 20121005,
        "issueValue": "LTDILWGY",
        "scanName": "Company Stored as Person (Given Name)",
        "severityCode": 1,
        "severityName": "High",
        "totalDiscovered": 1
    },
    {
        "dateDm_id": 20121005,
        "issueValue": "YMORCLTD",
        "scanName": "Company Stored as Person (Given Name)",
        "severityCode": 1,
        "severityName": "High",
        "totalDiscovered": 1
    }
]
}

console.log(b.SearchWithMasterDataDIdAndScandefinitionDAO)

var returnVar = {}
b.SearchWithMasterDataDIdAndScandefinitionDAO.forEach(function(item){
    var thisItem;
    if(returnVar[item.dateDm_id] == undefined){
        thisItem = [];
    returnVar[item.dateDm_id]  = thisItem;
    }
    else 
        thisItem = returnVar[item.dateDm_id];
    
    var obj = {};
    
    obj.issueValue = item.issueValue;
    //and so on..
    
    thisItem.push(obj);
    
});

console.log(returnVar);