It’s a good question, be interesting to hear other people’s comments.

In my mind, I don’t think you can retrieve the user’s current selected company from a database API because this information is not stored on the database level.  When an user switches between company A to B to C in the application, this information is only available from the client side and is then typically passed into an argument of a database API call but it is all done on the client level.

The only thing you can retrieve that I know from the database is the default company assigned to the user via User_Finance_API.Get_Default_Company_Func.