Dear Sadhaka,
To filter by frames, you have to either create a Local frame, or click on an existing Master frame (the first drop down selector), and choose Unlink. The frame will now be changed to a Local frame, where you can filter players, and/or flows.
The other way to get filtering is to edit the Master Page in Engrave Mode (by double-clicking on the Master Page “First” or “Default”) and select the filtering options.
I’m in total agreement with you on the “love” for Dorico!!!
