[Down arrow}+[Selected note] (Map view only)
[Cmd]+[Down arrow]
[Cmd]+[Opt]+[Down arrow]
[Down arrow]
[Double-click] (viewport part of Map containers and agents)
Logical opposite of Expand View. Acts like a 'Down Arrow' for Map views. Only works if a note has active focus. There is no menu reference to this shortcut.
In other views, drilling down selects the first child of the current container.
All map shortcuts work even if a container has its viewport hidden by expanding the title area.