Hei! I have been frustrated about the fact that bookmarks management was way easier in previous versions of Opera, as far as I remember.
However, I found an extension that I hope can help those of you who want a simple solution.
About the extension
Size 9.8 KB
Last update Nov. 17, 2014
License Copyright 2014 escape75
I JUST INSTALLED IT, AND IT WORKED JUST FINE.
SUPER-EASY TO USE