Solved Category & Sub-Categories

Seems like it should be simple to do:

From the navigation menu select a link which is a parent category. This would take me to a page where the sub-categories of the parent are shown. When you click on the sub-category of your choosing, you are taken to a page of all the products of that sub-category. Would love to be able to do it without having to assemble each page manually. Maybe achieve the result with a plug-in, shortcode or with a module.

On this site https://www.monsterdisplays.com/ under "Featured Display Styles" you see some parent categories (on my site those choices would be in a menu) if you select those it takes you a sub- category page etc...

How can I achieve this in Divi?

Thanks in advance.