[{"_id":ObjectId("614e1b600146c86a7d5cb524"),"hash":"hash_1","logs":[{"address":"address_1","topics":["AAA"],},{"address":"address_2","topics":["CCC","DDD"]}]},{"_id":ObjectId("614e1b470146c86a7d5cacd0"),"hash":"hash_2","logs":[{"address":"address_3","topics":["EEE","FFF"]}]}]

db.collection.aggregate([{"$match":{"logs.topics.0":"CCC"}},{$project:{hash:1,logs:{$filter:{input:"$logs",as:"log",cond:{$eq:[{$first:"$$log.topics"},"CCC"]}}}}}])