How to collapse/expand a notebook stack in the shortcuts menu.

[tmsbn90 0]

Is there an easier way to expand/collapse a notebook stack on the shortcuts menu on the sidebar without using the right click menu? The windows version displays an arrow to the left of the notebook stack (when you hover your mouse over the name) which can be clicked to expand the stack easily.

[erik09 1]

I'm also wondering about this. 

Instead of clicking on the small arrow to close one's notebook stack,

it'd be great with a shortcut for this.

Best,

Erik