Separating a library in two independent sets in the Calibre interfase

Hello.

I have a large collection of fiction and nonfiction books mixed with a large amount of tabletop roleplaying games ebooks that I would like to keep separated, so when I used the search function, there should be no overlap between these ebook classes quickly.

Is that possible? How could I do that? Please, mind that I have no experience in programming, but I'm willing to mess around fiddly bits, if people could give me some instructions.