Metamodel extension

[thedrake]

Hello,

My goal is to draw a functional architecture.
I want to create a new element named "functionality", which is contained in a "functional zone" which can be in another functional zone.

I made a profile, extended the functionality and the functional zone from Package diagram (to allow containment).

But it seems that I cant go any further. I would like to link these two stereotypes like in a metamodel (Functional zone to itself with an aggregation link 1..n) (Functional zone to Functionality with an aggregation link 1..n) but these links are not available.I understand that this is the limit of metamodel extension in Sparx, and It can't validate a model with my metamodel, or alert the user when he's not respecting it. Is it right ?

Thank you very much for your help.