Limiting related posts to a specific tag

Is it possible to use a combination of a tag and categories to determine which related posts are used?

Here’s my situation: My site includes both original site and curated news. I’d like to include only original content as related posts.

I use a specific tag to denote original posts. So I’d like to set up the plugin to look for posts using that tag and then link to other posts using the same category.

Is that available — or is there another way to limit the related posts to just original content?

Thanks.