interesting question which cannot be answered easily as the data for it is spread over different tables.
And basically there are two approaches:
The first one is following the roles a user has and via table license_role you could find out which type a user is. The problem with that approach is, that a user can have roles from different types (by the way: there is no "Approver" type anymore, it's now called "Business stakeholder") and also there is no relation to the subscriptions the instance is assigned to.
Therefore I prefer the second approach. At first you have to identify the right subscription (product) you are referring to. Go to table license_details_item and enable column "Product Code":
Take the code you want to refer in the following report. Whether the purchased licenses are of type "Fulfiller" or not depends on the product. For example for CSM and FSM all licenses are of type "Fulfiller". That's the reason why there is another subscription for "Business Stakeholders" because a large number of users perform only restricted activities as a kind of approver.
With that code you could create a report on table ua_app_usage which is the real treasure for you:
Maik
