Originally Posted by rav555
What I would like Calibre to do is allow the creation of "sub" libraries that can contain, History, Sci Fi, Biographies or any other topic or grouping that I can create, etc. Or maybe I can do that but I just don't know how.
Look at tags, saved searches and restrictions. Together those will do what you want (you tag books with the genre(s) you want, create saved searches matching the genre tags and use those saved searches as restictions).