Dynamic data - how?

I have Users database. I have User Groups database. In user edit window I can’t make application to select User group by itself - based on users group’s value from database.

Help would be appreciated.

Set default to current user group. But from what I see in your DB, existing users are not linked to any group

Thanks for reply, but your answer is not correct.

I’ve managed to figure it out. As stated in Reference: “Default vale should be of the same type as the type of content defined in ‘Type of choices.’”, so:

Search for User Grupe[unique id=Parent group's User's Grupa]:first item

…did the job.

Thank you.