The navigation side-bar displays the document headings using a tree widget, with lines from parent to child and collapse/expand widgets for items with children. However - in the cross-reference insertion dialog, while we do get indentation of items (for LTR text anyway, see 131725) - we don't have these two elements of parent-child lines and of collapse/expand. It would be useful to have them (although with care not to increase spacing between lines, as the number of items viewable at once is already not so high.)
But it's not needed to get see the full outline, you just pick one item from a list. Doubt anyone would collapse the tree.
(In reply to Heiko Tietze from comment #1) > But it's not needed to get see the full outline, It helps see the whole outline if the outline has a lot of items. It also helps you understand what level an item is on even if it is not numbered. > you just pick one item from a list. So why even make the widget taller than a single row then? ... :-( > Doubt anyone would collapse the tree. 1. I would. 2. There's a second motivation, which is more visibility for the outline level of the item.
Hm, why not...