Hello Patrick,
Can you share more information about how is the connection configured? Relational to BW or relational to HANA?
I guess it is relational to HANA so you should be able to access the list of your HANA models (Analytical Views, Calculation Views).
Then the application will check your user authorizations if SSO http://scn.sap.com/docs/DOC-36305 or just take the ones from the user in the connection. You might be able to access the list of models but not allowed to see data as an example
For BW, they can generate models and authorizations (Analytical Privileges) so if you want to leverage them, you will need users in HANA. See more infos below:
http://www.saphana.com/docs/DOC-3151
Hope this makes things a bit more clear. 
Alex