If you were using a custom 3 level class hierarchy where each class on level 2 is based on a class in level one, and each class in level 3 is based on a class in level two how would you populate an aggregate class with members?

For example, In level 2 I have a container subclass of the container class in _base.vcx let's say. Now I want to create in level 2 a subclass of the container class with some contained classes inside it. Should the new container subclass from level one or level two and should the contained classes subclass classes in level one or two?

Assume level one and two classes are fairly similar in properties and methods at this time. One theory I might use is that since everything in level 2 is basically subclasses from level one, I should do the same with any class in that level, but if my new class is a specialization of its parent, then shouldn't I specialize off the current level? Or should a significant specialization of a level two class go into a second dimension vcx library?

What's the difference between classes category and oop on the forum?

TIA