Navigate the Outline with the Keyboard

I would like to be able to navigate the outline with the keyboard.

Currently it is possible to use the up and down arrow to move up and down the notebooks in the outline. But only for those that are visible (not collapsed).

My idea is that the left arrow would collapse all descendants of the selected notebook and the right arrow would expand to the children of the selected notebook. More or less like in Windows Explorer TreeView.


I can't believe this is not available. In fact, now when I try to navigate notebooks with the keyboard, the focus shifts to the notes within a notebook and I couldn't find a way to switch back. Left & right arrows also do not open and collapse notebooks - something which is an industry standard.