[{"postId":ObjectId("62dffd0acb17483cf015375f"),"userId":ObjectId("62dff9584f5b702d61c81c3c"),"state":[{"id":ObjectId("62dffc49cb17483cf0153220"),"notes":"these are my custom notes!","lvl":3},{"id":ObjectId("62dffc49cb17483cf0153221"),"notes":"hello again","lvl":0}]}]

db.collection.update({"postId":ObjectId("62dffd0acb17483cf015375f"),"userId":ObjectId("62dff9584f5b702d61c81c3c")},[{$set:{state:{$cond:[{$in:[ObjectId("62dffc49cb17483cf0153221"),"$state.id"]},{$map:{input:"$state",in:{$cond:[{$and:[{$eq:["$$this.id",ObjectId("62dffc49cb17483cf0153221")]},{$eq:["$$this.lvl",0]}]},{$mergeObjects:["$$this",{"notes":"new note"}]},"$$this"]}}},{$concatArrays:["$state",[{"id":ObjectId("62dffc49cb17483cf0153221"),"lvl":1}]]}]}}}])