Currently you can via a variable point to en external data source. I use it to load very large log files hosted as a FM file on FMS. Once you have the variable set, and the file is opened you cannot change it without closing the file and re-open it. Changing the variable value does not open a different file
A function to close all windows who has the file open and reload the external data sources with a new reference would be very helpful.
This would also work great in a multi tenant system. Based on the login a specific database is referenced and opened.