Writing out performant queries for n-relationship queries on a single node where n > 2

So are you looking for a query that finds a user within 3 hops, but doesn't continue expansion once it encounters a user node? In that case you may need to add a predicate to ensure you filter out such results:

MATCH path = (u:User {uid: $uid})-[*1..3]-(t:User) 
WHERE single(node in tail(nodes(path)) WHERE node:User)