Aggregate function on different nodes to evaluate condition for multiple nodes

I have a Neo4j database of Reddit over a specific time period.
Metagraph of the database

I start from a specific subreddit, let's call it X. From X, I define the top_users of this subreddit as the users who have at least 1 post with a score higher than the average score of posts on this subreddit. Next, I want to look for the other subreddits where the top_users of subreddit X are also top_users but now based on the average score of those subreddits' posts and the top_users' posts on those subreddits.

This is what I already have, but not sure how to proceed. How should I best do this query?
Thanks for the help!

MATCH (p:Post)-[:Submitted]->(:Subreddit {display_name: 'X'})
WITH avg(toFloat(p.score)) as score_avg
MATCH (u:User)-[:Submitted]->(p:Post)-[:Submitted]->(:Subreddit {display_name: 'X'})
WHERE p.score > score_avg
WITH DISTINCT u as top_users
MATCH (top_users)-[:Submitted]->(:Post)-[:Submitted]->(sub:Subreddit)
WITH sub as top_users_subs
MATCH (p:Post)-[:Submitted]->(top_users_subs)
WITH avg(toFloat(p.score)) as subs_score, top_users_subs