Wordpress "previous_post_link" and "next_post_link" within same child category

[charliechocolate]

So far I couldn't figure this out after so much trying. I would like to restrict "previous_post_link" and "next_post_link" in single.php to navigate only within the same child category and stop when the last post is reached. It only seems to work with parent categories so when on a subcategory, the navigation links take you through all subcategories of their parent without any navigational order (I could live with this if it followed the menu order and not jump randomly from one category to another)

 

An alternative code to substitute "previous_post_link" and "next_post_link" would also be great if anyone knows a way around this.