Compound document(child) inside of a compound document(parent)

This user story will cover the aspect of having a compound inside a compound doc. 

• As a user, I need to be able to create/upload a compound document to be the child of another already existing compound doc.
• As a user, I need to be able to upload a .zip folder with a hierarchy of compound inside a compound in it.
• This user story is valid for the "product design" use case: When I upload a design file which is a compound file as it contains a preview of the design, and the various textures (materials), I need to navigate those textures and see what they are. Those textures (material files) can already exist in the system or be new.