View Mode: Selected Regions
Set the piano roll to show notes/events from the selected regions as opposed to the focused track. The vertical line showing the MIDI regions is very useful. Who said all MIDI regions had to be the same color?
The control of the view is in the “View” menu of the Piano Roll.
View multiple regions in the Piano Roll Editor in Logic Pro — Apple Support
Notes from all of the selected regions appear in the Piano Roll Editor. The start point of each MIDI region is indicated by a vertical line of the same color as the MIDI region itself.