Composition Deck/Card Macros don't work in user macros?

Purpose

Composition Deck/Card Macros Don't Work in User Macros?

Answer

This is caused by the limitation of Confluence 4.x itself, where it doesn't render the macro as the way we did for a nested {deck} and {card}.
 
Alternatives:
Insert a live-template (with nested deck) inside a main template with an outer deck.