Correct folder structure when saving books to file

Hello...

1. I have this books (screenshot from tag browser):



It seems to be O.K. It's what I want.

2. I have these setting in Look and Fell/Tag Browser:



3. I have these settings in Preferences/Saving books to disk:



4.When I do a "save bokks to disk" action, I get this folder structure:



5. But I want to have this folder structure:



In other words, I want a folder "Historia" and inside it, two ohter folders: "Argentina" and "Espanya". But what I get is two folders: "Historia.Aregntina" and "Historia.España".

Please, what I'm doin wrong?
I'll be very gratefull for any help.
Thanks in advance.

Best regards,

Otriades