We often get requests for indented or hierarchical bookmarks, and it is high on our feature list.
Until the feature is built I use a simple and very effective workaround to separate out top level and second and third level bookmarks.
To set the scene, if I am marking up a case, I may want to add a bookmark for each section of the judgement (‘Facts’, ‘Submissions’ ‘Discussion’ etc) and then under those have sub-bookmarks for particular issues (‘Ground 1, Ground 2, etc).
I simply use dashes (normally in batches of 3) to indent the bookmarks. I also use capitals for really top-level markers (like Judge’s names). The result is a list of bookmarks for a case that may look something like this:
You can see that it is now much easier to find the bookmark you are looking for with a quick glance. Try it!