[chaley]

Originally Posted by nikoski

It seems that your last hint (create a custom column "Text, behaves like tags") won't give me a hierarchical structure in the group "cc_genres" like this:
cc_genres
--------->2
------------>a
--------------->b
...

It can in CC, to the extent that CC supports hierarchy, even if it isn't hierarchical in calibre if you add the group to CC's Hierarchical Groups setting . In addition, if you want you can also set the column to be hierarchical in calibre.

BTW: What does "...behave like tags" mean in this context?

It means that the column can contain many values, like tags, instead of one value, like title.

Another approach could be to create a second hierachical structure for the sync to cc only:

- create a column like "cc_books", set it as a hierarchical one in calibre and cc,
- create a second hierarchy whithin and add to it the books that i want synced to cc
- in cc make only this column visible

The drawback would of course be to have 2 parallel structures.

This is basically what I suggested. I didn't see the need to turn on hierarchy in calibre, but doing so doesn't hurt anything. I also suggested that you add items to the group when you do searching because you seemed to indicate that you know what you want in the group when you do searches. Of course, you can add items whenever you want.