Display intermediate function results, not only combined ranking score

We've build a newsfeed based on Elasticsearch. To be able to rank the posts we combine (multiply) several functions (think about time decay, number of likes, ...). This all works perfectly, but as with most algoritmes it's an art to set the right weights for every function to get the best possible ranking.

Therefor we would like to give our developers/testers advanced insights in why which posts ends up in a certain place in the ranking. The best way to do that would be printing the results of each independent function on the screen next to the post.

Is there any way to get from Elasticsearch not only the final (in our case) multiplied and combined result back, but also the intermediate results (result of each function used)? We're currently at version 6.8 (but updating is possible if what we need is only available in 7.x).

Any ideas?