Export only selected bookmarks/folders from Firefox

[Swamp Thing]

TL;DR Summary

How can we export selected groups/folders of bookmarks from firefox into a file?

There is a discussion here
https://support.mozilla.org/en-US/questions/831118
referring to a solution called Xmarks, which is now defunct.

Someone has suggested doing this:

You can create a second Firefox Profile Folder that doesn't have any bookmarks.
If both instances of Firefox are open then you can copy and paste that folder or selected bookmarks from the Library of one instance to the Library of the other instance and export that selection to an HTML file. That is what I would do in this case. You need to open the second instance with the -no-remote command line switch.

... but it doesn't work for me. When I copy-paste from one profile into another profile's Library, nothing happens. If I drag and drop, again nothing appears in the target area.

Any solutions that, preferably, don't involve add-ons or 3rd party stuff?

==== EDIT ===
I just found that I can copy-paste or drag-drop a single bookmark from one profile to another.
But if I try to select two or more bookmarks, or if I select a folder, then it won't copy across.

 

[Dr Transport]

export everything and go in and delete out what you don't want...

 

[Swamp Thing]

export everything and go in and delete out what you don't want...

Thanks...
Yes, it seems that is the only option right now.