Access Point will display all the documents any user is Authorized to view.
If you want a single application with different granular data or different objects in the front end depending in the users (Sales or Marketing) You can solve all of this with Section Access.
Enable data reduction under System Document Properties, On open Tab in order for granular data reduction.
To manage the front end experience I suggest you to create FLAGS (Island fields with 0 - 1) value so you can create visibility conditions for your objects. Ofcourse this FLAG fields must also be inside Section Access.
If you go for data reduction under Section Access you should be aware that your memory usage will not be really efficient since you will always deploy the full data model in memory, once it has been deployed, data is reduced (but not erased from memory)
Good thing is that having only 1 QVW will allow all your users to share objects. If you create different documents for different users, they will not be able to share objects.