Reading a "Learning Neo4j" book from Packt publications. Found a query:
match (p:Person)-[b:BOUGHT]->(prod1:Product)-[:MADE_BY]->(br:Brand)<-
[MADE_BY]-(prod2:Product)
with p, br, prod2, count(prod1) as NrOfBrandProducts
where not(p-[:BOUGHT]->prod2)...