Moving nested bookmarks

Is there a practial guide on how to drag nested bookmarks? It is relatively easy to drag one bookmark so it is "nested" under another bookmark. But it is NOT easy to go the other direction. I am looking at huge PDFs with hundreds of bookmarks, many of which are nested under other bookmarks. Some of those are incorrectly nested and I'd like to "drag them out" (I have no idea what the right words are to describe this, so I hope you are following me). But DC will not let me. Any tips for how to do that would really help.

Also, it seems by holding down the shift key then clicking a range of bookmarks, I can then nest that range under another bookmark, unless some of the bookmarks in the range selected includes nested bookmarks. Is there a way to nest a range of bookmarks, when some of the bookmarks I want to move are already nested?