What I am trying to do is Search for "Fansites" that are also the "Asian" category or vice versa. When I select both categories it just shows me all the torrents that are Fansites or Asian instead of both at the same time. Is there some way to search for torrents that include both categories?

You can do a regular Google search specifying this site and use search operators such as "+".  "Fansite" doesn't return results, so you have to name specific sites.  Might help to use more specific terms than "Asian", too, and you can use "or" as a search operator.

https://www.google.com/search?q=asian+%2B+onlyfans+site%3Agaytor.rent

guide:  https://support.google.com/websearch/answer/2466433?hl=en