sub categories for Brine?

Hi all, I just posted this in another section to ask if it was already possible to do. But I am thinking not, so I figured I would ask here.
Basically I wondered if there is code to create sub categories within the version 7 Brine template. I am new here so I wasn't sure if it is as easy as that or tons of work, when entering one lot of coding does it throw everything out etc..
All information is appreciated!
This is specifically for product pages by the way, so for example after clicking mens clothing from the category, it would be nice to then have the option of trousers, tops, shoes etc.. Hopefully that makes sense.