How to use of an instance of a class in another class

Question

I have three separate library :

1. Export.js : that written all export methods
2. HamburgerMenu.js : Export.js used here
3. Loding.js : display spiner to prepare export file

Created an instance of Export.js in HamburgerMenu.js then a method of instance passed through Loading.js to run method. But there is an error in Loding.js that can not access to editor in Export.js.

Export.js and Loading.js hasn't direct relation.

How can i solve it?

Export.js

class Export {

    constructor(editor) {
        this.editor = editor;
    }

     exportGeometry() {

        var object = this.editor.selected; // return error : editor is undefined
       ...
     }
}

HamburgerMenu.js

import { Export } from './Export';
import { Loading } from './loading';

function HamburgerMenu(editor) {
   var exportModule = new Export(editor);

   var loading = new Loading('Please Wait..', 'Preparing to download ...', 
        exportModule.exportGeometry);
   
}

Loading

class Loading {

    constructor(title, message, Fun) {

        this.title = title;
        this.message = message;

        Fun(); // Fun here is exportGeometry that passed from HamburgerMenu
    }