[{"_id":ObjectId("6079bab4f297df39a44609cb"),"title":"Test messages of single user","messages":[{"_id":ObjectId("6079bab4f297df39a44609cc"),"body":"Test 1","status":1},{"_id":ObjectId("6079bab4f297df39a44609cd"),"body":"Test 2","status":1},{"_id":ObjectId("6079bcf7c041b00ec4cebb9d"),"body":"Hello I'm Sam","status":1}]}]

db.collection.update({"_id":ObjectId("6079bab4f297df39a44609cb"),"messages":{$elemMatch:{_id:ObjectId("6079bcf7c041b00ec4cebb9d")}}},[{$set:{"messages":{$map:{input:"$messages",as:"m",in:{$cond:[{$eq:["$$m._id",ObjectId("6079bcf7c041b00ec4cebb9d")]},{$mergeObjects:["$$m",{status:2}]},"$$m"]}}}}}])