Ember naming for parent/child objects

I am trying to understand how naming works for parent/child objects in EmberJS.

Say I have 2 controllers as below;

// controllers/flash-messages.js
// controllers/posts/view.js

Now if I want to access "flash-messages" controller inside my "view" controller, I can just write the below in my controllers/posts/view.js

needs: ['flash-message'],

However, now assume I have one more controller as below (in sub-folder)

// controllers/posts/flash-messages.js

Now how do I distinguish between the 2 "flash-messages" controller ? Is there any way by which I can refer to each of them uniquely ?

Also does the same concept apply to models & routes ?