WP in Subfolder. Htaccess and Redirects? Help!

I have a domain — https://www.domain.com.

That domain points to a subfolder in the root of my host’s server. https://www.domain.com = username.host.com/subfolder.

In that subfolder I have WP installed, which is all fine and dandy, but my problem is the links in the site. For instance, when you mouse over the links in the nav, they say username.host.com/subfolder/category/categoryexample whereas they should read https://www.domain.com/category/categoryexample.

So my question is how do I get my links to correctly reflect the url of the site? It has been suggested that I put a redirect in the htaccess file, but that’s where I get lost. Can anyone walk me through this?

Help!