I got something like that:
MATCH (a:A)
WITH a.id as `aId`, a.acRef as `acRef`
MATCH (b:B)
WITH b.id as bId, b.bcRef as `bcRef`
MATCH (c:C)
WHERE acRef=c.aRef and bcRef=c.bRef
RETURN aId, bId, c.id as `cId`
but ofcourse it doesn't work because I'm no...