Loop in posts with same taxonomy term as current post, from category X

I already have this almost working, with a neat snippet someone helped me with. Currently though its displaying all posts regardless of category or post type with the same taxonomy term as the current post. I would like to change it so I can specify which category it should loop in the posts from.

This is what the code looks like:
https://pastebin.com/pM8aFPQ9

I realise this is probably pretty easy to do, but I dont know where in this code I should specify the categories or how I should write to do that. Can anyone help me with this?