What CSS do I use to create a third drop down menu?

Site URL: https://meadowcollective.com

Hello, I need the additional CSS code to create a third drop down menu. The theme I have chosen doesn't allow for a third categories of drop down (so, when I hover on clothes, and then hover on the drop down page of accessories, I can't create new pages specifically for jewelry and rings, and I'd like to be able to do that) Can someone please send me the additional code, so that I can do this for my website.