In node.js how to require the modules which are not in the same folder of current file

The below is my node.js project structure. In the folder "lib" I have "Notification.js" file, in which I want to require the "index.js" file. If that index.js file is available within the lib folder, I can use var module=require(./index). But now it's not available outside of the lib folder.

   MyProject
      |
      |
      index.js
      lib
        |
        |
        Notification.js

You can use relative imports. In your Notification.js:

var module = require('../index');