Over time I have ended up with quite a lot of bookmarks organised by themes and activities in various folders and subfolders. Naturally, the borders between themes can be porous, overlapping with one another. Duplicating a subfolder implies that eventually the duplicates will not be filled up with new bookmarks as time and attention are limited. Rather than duplicating, it would be better to insert shortcuts to the selected subfolders, or that folders can share subfolders. Either case would lift the issue created by the fact that themes overlap with one another and it is practical neither to ignore this situation, nor to duplicate subfolders of bookmarks.