(2021-04-09, 2:32)Michael Horvath Wrote: How do I enable that section?
Go to View -> New Source Window. You can dock it by holding down Ctrl and dragging it where you want. Once you have the various windows docked that way you like I recommend you lock them by going to Prefs -> GUI -> Lock docked windows. You can still resize them horizontally or vertically if needed but you wont accidentally undock them with a click and drag.
(2021-04-09, 2:32)Michael Horvath Wrote: It is an MPD model with submodel tree. How do I quickly select the current submodel's parent?
Roland can correct me but I don't think there a good way to "see the tree". You can, however, see all the files in the current MPD in the part bin area by selecting Model (content) overview information groups -> Content of current session's file