Thank you both for your replies. Somehow I did not find the "how to transfer" link on my own.
My old calibre set-up contained multiple libraries. Those libraries are organized broadly by subject. Each library in the old set-up contains a "cgenre" column to further subdivide the contents.
Can you suggest an efficient way to re-configure the new set-up to use one library and metadata for creating subsets?
I understand if this question is more than anyone wants to answer

. If there were a
Calibre for Dummies book I would buy it.