Filter posts on a page in Network theme

I know there are many threads about this but I have yet to find a third party plugin to achieve what I want to do. I am using the Network theme and I really like how the posts are shown on my home page. I would like to have a post describing each of my premium themes and pro plugins.

To present these features to customers I would like to have a theme and a plugin page that would filter by a category on each page. Themes for the theme page and plugins for the plugin page. Currently both pages are showing posts from both categories.

I was hoping there is a way to create a child theme to use the functionality built in to the Network theme to display the plugins and themes on each of the pages the way posts are shown on the home page. Alternatively, I could live with the way they are showing on the pages currently if I could just filter the post… Thanks.