MATCH (t:Timetable)<-[:BASED_ON]-(n)-[:REL_1]->()
WHERE id(t)=1234
optional MATCH (n)<-[:LIGHT_SETTINGS]-(sc:Scheduler)-[:REL_2]->(e:Equipment)-[:TYPE_OF]->(et:EquipmentType)
OPTIONAL match (e)-[:PARENT*]->(si:Site)
RETURN n.`_entity` as referenceTy...