Tulip user table

I am trying to accomplish a similar goal on creating a query and aggregation on the user table. I would like to create a query and aggregation to make a list of users that have a specific ‘Title’ for a custom field. This aggregation list would then be used as the data source for the selection options of a single select widget. My intended use is to be able to select a user from a dropdown list that all share the same ‘Title’

It seems like it is partially implemented with no actual way of to actually create a query.

I looked into the functionality of ‘User Groups’ and created a group of these users to see if it accomplishes my needs. However it does not appear that any user group data is usable within apps. The Knowledge Base article shows that the groups are only usable for approvals and E-signatures - Create and Manage User Groups. Is there a method for referencing members of user groups within apps?