So we are working on a project using marionette and we have made a good progress so far, but we struggling with a part of the marionette nested view model,
so lets assume that we have an apartment (represented as a composite view), and the apartment contains a collection of rooms and a collection of chairs, what we want to do is have the rooms and chairs a direct descending of the aprtment composite view, how can we do this, knowing that the composite view can only have one child collection, should we be using regions?
You can do this with nested composite views. For the use case you described you could nest a compositeView for your Apartments and Rooms.
Fiddle: http://jsfiddle.net/yCD2m/23/
Markup
JS
Have you tried using a Layout instead? it supports regions and an itemview (if needed). The way I am using this is to define several regions in the layout; show a collection view or item view in each region and any other apartment stuff in the layout template. so, for your example, your apartment layout would contain all of the apartment attributes, and a chairs region would contain a chairs collection view, and a rooms region could contain a rooms collection view.