how to retrieve caller function js file global variable value in nodejs

Sample Code from nodejs:

Code from JS1.js :

var js2=require("../../util");
var dataName="Billy";
function hello1(){
   js2.hello2("message");
}

Code from JS3.js :

var js2=require("../../util");
var dataName="Tom";
function hello3(){
   js2.hello2("message");
}

Code from JS2.js :

exports.hello2=hello2;
function hello2(arg1){
   console.log(arg1);
   //Here I need the data in global variable "dataName" of file JS1.js or JS3.js
}

I need to access the global variable of caller js file.