Špatně jsi četl, co je napsané v tom mém odkazu. Mi to funguje.

How to copy one or more folders from one profile to another:

Just like we can usually copy text in one application and paste it someplace else, I discovered (over the past few days) that the same thing happens when trying to copy Ffx bookmarks folders between separate Ffx profiles.

(1) Open Ffx for the two profiles to be copied from and copied to.

I always start Ffx using the profile manager, due to having several profiles, so to be able to open a second instance
of Ffx with a different profile, a desktop icon was created with the following command, which I only learned of over the past few months.

"C:\Program Files\Mozilla Firefox\firefox.exe" -P -no-remote - možná změnit na Program Files (x86) - podle umístění aplikace Firefox

(2) Open the bookmarks manager for the profile to be copied from and then do the same for the other profile.

These surely don't need to be both opened at the same time, but I don't have a problem with this; unless too many applications were opened and the Windows taskbar was full or too full.

(3) Go to the bookmarks manager of the profile to be copied from, select the folder or folders to be copied, right-click and then select copy.

This bookmarks manager can surely now be closed without causing the copied folder to be lost, but I'm not going to bother testing this for it's a non-concern. It can wait.

(4) Switch to the bookmarks manager for the profile to be copied to, select where the copy is to be pasted, right-click and then select paste.

(5) Close any bookmarks managers that are still open and then close the Ffx browsers, or don't; depending on what you now want to do.