i'm using something like that :

SubModel,CollectionSubModel

MainModel { subModelCollection : CollectionSubModel }

ViewSubModel { model: SubModel, collection: MainModel.subModelCollection }

ViewSubModel listens model and collection ( using model.bind() and collection.bind() ). If someting happened, which should inform all submodels i fire an event with a collection.trigger(). Say if i want to hide MainModel, MainModel's View calls model.subModelCollection.trigger('hideParent') before remoing it's "el".

* : i'm sorry if you confused because of my explanation. i tried my best.