You can do this through Fusion (fusion makes the discovery and writes it to a custom field/s on the user). Otherwise, it would be a case of creating a dashboard that isn't at the user level, but incorporates all those objects, and then you would have to log in as the user to see everything the user can see.
We used to have the ability to create custom dashboards on the user that would incorporate this kind of info, in order to make it easier for users to run this sort of query, but when Workfront switched over to the "new workfront experience" the functionality didn't transfer over.