I have the following Firebase hierarchy.
How can I write a query which finds the child where the value is 1
AND I don't know that it is under the node V9T3cEgEGPRmIkMQb32hxa5gG7L2
? In this case, I want to find and print out -KeYbk3K1xXlyzOGVVPx
(this uid key is generated by Firebase). The main node is eventUser
.