Many websites are tagging their content with more than one category term. Listing other content marked with the same term is a very common task in Drupal. But with a multi-valued field storing more than one Category on a single article things are a bit more complicated.
Complexity increases with the request to sort the list by relevancy, showing the most relevant related content on top of the list (the articles that share more of the same tags).
This article lists the steps in Drupal 8 Views to create a list of related content titles sorted by the number of tags shared with the content currently viewed.