I understand that the syncing part of this browser is in beta (under development). I am using the Brave Browser Beta Build. That being said, this post is not for support, because I know the Brave Team is aware of this problem, and they are working hard to get it fixed.
So, do not try to organize your bookmarks, nor try to figure out how to because it might be a waste of your time…Lol. I just wanted to say that.
Also, I wanted to say that the Brave team is doing a great job and working hard to make this browser a great one. For me, out of the box, it is a very good browser.
To the Brave team, Thank you, and keep up the good work!