Allow to organize bookmarks in multiple folders / menu-levels

The rough idea is to create bookmarks normally but after it spawns in the list (and possibly spawn a dialogue for this also) we should be able to put any bookmark as a child of another bookmark. An example would be for bookmarks to project directories going under the bookmark to the directory named as the server it is pushed to like this set of bookmarks:

gitlab.com bookmark: ~/projects/gitlab.com
  project 1 bookmark: ~/projects/gitlab.com/project1
  project 2 bookmark: ~/projects/gitlab.com/project2
  ...
github.com bookmark: ~/projects/github.com
  ...

You get the gist. This would be more convenient for people like me who make a lot of bookmarks and sometimes have difficulty finding the bookmark that after. I only plan to use 2 levels of bookmarks if this is implemented. As an aside one of the ways of setting bookmark parents should be drag and drop.