Having issues customizing users and roles for new users.

Here is an example. If i can solve the below step by step i would be able to customize anything, i believe. QB support has been bad so far.

How can i customize an user so he can mark bills as paid and at the same time to have access to see the payables aging summary and detail? Roles are in "bill payer" and "view report". But cant figure out how to add functions from one type of role to the other.