Sync a directory out of ~/Nextcloud


I’m running Nextcloud Desktop Client version 2.6.4 on Trisquel 8.

I sync things inside my local /home/myself/Nextcloud directory with my Nextcloud server.
Now I would also like to sync my local /home/myself/.additional-directory with my Nextcloud server too.

When I use the Add Folder Sync Connection button and select my /home/myself/.additional-directory, it ends up duplicating it into /home/myself/Nextcloud/. So I end up having ~/.additional-directory and /home/myself/Nextcloud/.additional-directory.

How could I have an additional sync directory located out of ~/Nextcloud and make it sync directly with my server without duplicating it into ~/Nextcloud/?

Thank you.

I think I did a too complicated writing. Let me please try again:

How do you sync an additional directory?