Bookmark Can't Deselect
In the Bookmarks panel, when trying to set a bookmark, occasionally, a bookmark will be selected and there is no way to "deselect" it so you can create another top-level bookmark. Any bookmark you create becomes a child of the currently selected bookmark. There should be a way to deselect the current bookmark from the panel so you can add another bookmark without it being a child of the selected one.
I'm a little late to the party, but I just figured this out. CMD+Click the bookmark