I have order objects indexed with the client id and the order's items.
I'd like to know what products recommend to a client based on the items he bought, using a collaborative filtering
I'm new to elasticsearch, and I'm following the example from here https://qbox.io/blog/building-simple-recommender-systems-for-elasticsearch-1 but I still don't know how to personalize my query based on:
 I don't want to make two requests, one to get the items he bought and then construct the query filter in agreggation. I'd like to make a query inside the filter that gets all items a cliente has bought even they are from different orders.
 I also want to make a personalized filter, based on combinations of items, since having orders containing all the items a client has purchased is practically impossible.
e.g, a client has a purchase history of 5 products (in different orders), so I want to boost results like:
- products from orders that have those 5 items have a greater score
- products from orders that have 4 of those 5 items have a slightly lower score
- and so on