DMG files within parent app

I am new to programming with Xojo but I have programmed with in college. What I am trying to accomplish is build an app that houses links and copies of DMG files within the app based on our license with the developers of tools we use. In my app for OSX how can I package it with another dmg files so that when a user clicks the button depending on the license it either launches a download of the resource dmg or launches the dmg from a folder within the parent app?

Thanks in advance!