Hi, there.
I learned how to manage book categories by using subgroups from this
documentation. It is really one of the best features of Calibre for me.
However, when importing hundreds of books from folders, it can be quite tiresome to assign books to particular subgroups since it can only be done manually, correct me if I'm wrong.
I hope there would be a feature that will automatically add subfolders as subgroups when importing books from folders.
Thanks.