[{"_id":1,"layoutName":"asd","contests":[{"externalId":2,"thirdPartyEventId":3,"name":"asdsad","rounds":[{"_id":123,"thirdPartyId":23,"externalId":2,"heats":[{"externalId":5,"name":"hjk","order":89,"categories":[{"key":8,"label":"^7",},],"runs":[{"thirdPartyId":8,"externalId":6,"name":"uy","order":8,},],},],},]}]},{"_id":2,"layoutName":"asd","contests":[{"externalId":2,"thirdPartyEventId":3,"name":"asdsad","rounds":[{"_id":123,"thirdPartyId":23,"externalId":2,"heats":[{"externalId":5,"name":"hjk","order":89,"categories":[{"key":8,"label":"^7",},],"runs":[{"thirdPartyId":8,"externalId":6,"name":"uy","order":8,},],},],},]}]}]

db.collection.find({"_id":1,"contests.externalId":2,"contests.rounds.externalId":2,"contests.rounds.heats.externalId":5},{"contests.rounds.heats":1})