[{_id:{genre:"suspense",},price:10210.6,data:[{subGenre:"Thriller",flag:true,},{subGenre:"jumpScare",},{subGenre:"horror",flag:true,}]},]

db.collection.aggregate([{"$project":{"_id":0,"price":1,"data":{"$getField":{"field":"subGenre","input":{"$first":{"$filter":{input:"$data",cond:{$eq:["$$this.flag",undefined]}}}}}}}}])