CoreData Bindings for NSPopupButton

I want to use a dropdown menu (perhaps an NSPopupButton object) to represent the hierarchical results of two Core Data objects (Genre and Movie) and their relationship. In my current data model, my Genre object has a one-to-many relationship with my Movie object.

Now I want to create the contents of the NSPopupButton to show a hierarchical list of genres and related movies:

Genre 1
    Film 1
    Film 2
Genre 2
    Film 3
    Film 4

      

        
        
        
      

    

Note that in the example above, only movie objects can be selected for the object (objects of the genre will appear, but will not be selected). Also, to complicate matters, I have an additional NSPopupButton that lists movie rental locations. The location selected by the user ultimately affects the genres and movies available in the second dropdown menu.

My guess is that bindings will keep me busy with this problem so far, and eventually I will have to populate the contents of the dropdown. I am posting here for thoughts and opinions on the best way to do this.