There should be no need for composite list hierarchies in the Hub. They can be built to "test" the actions, but after testing they should be deleted
Exceptions:
5.07-01a Validation purposes: If data is needed to be consolidated to check against source systems, although the flat modules with attributes can be used to sum data
5.07-01b Combining Source systems: Combining multiple source systems into one feed from the data hub to the spoke model(s)
Best Practice article:
Data Hubs: Purpose and Peak Performance
Questions on this topic? See 5.07-01 No Hierarchies in our Planual forum.