Can an inverse dimension be used as a source collection?
Yes, there is no difference between database concepts or collections produced by in queries. Particularly, inverse dimensions can be used as source collections of queries. The only specific feature is that inverse dimensions are associated with some concrete item (the current value of an instance variable), which has to be specified in the external context. (In the case of concepts such an item is formally the top item, which is the parent for all other items in the database.