The left list does not allow me to navigate with arrow keys. It allows forward (downwards) navigation but when navigation back (upwards) it does not allow to pass the section since it moves the selection to the first nested item.
Why not remove the first nested item, and move the content to the parent then? I don’t like to click something and the selection moves to somewhere else. Maybe the parent should not be a selectable item.
It doesn’t need to be foldable too. The list is pretty small. And I think a vertical scrollbar is going to appear there when needed.