javascript - Removing the individual row in child schema inside the array of parent mongoose schema -

i want remove child schema's row based on field , schema inside array of parent schema. have tried below code failed.can 1 resolve //code details use_list parent schema in array field called frr_list has array element schemas . , want remove individual row of child schema based on fren_id. //

//main parent schema  var user_list = new schema({    user_id: {      type: mongoose.schema.types.objectid,      ref: 'user_reg'    },    fren_list: [fren_list],    block_list: [fren_block_list],    frr_list: [fern_req_recieved_list], //asking array     frs_list: [fern_req_sent_list],  });      //child schema  var fern_req_recieved_list = new schema({ //fren req list    fren_id: {      type: mongoose.schema.types.objectid,      ref: 'user_reg'    },    fren_name: string,    dt: {      type: date,      default: date.now    },    status: {      type: string,      default: "pending"    } //pending, rejected,accepted    });      user.list.findone({ //parent document    user_id: currentuserid  }, function(err, user) {    ///below child inside array field , schema    user.frr_list.findoneandremove({      fren_id: requesteduserid    }, function(err, message) {      if (err) {        callback(null, false);      } else {        callback(null, true);      }    })  });

as understand can delete individual items of frr_list array this:

i assume deleting individual items of frr_list frr_id (which _id generated mongoose)

  
user.update({ _id: userlistid,                 user_id:currentuserid                 //filter record userlistid , currentuserid             },
          { //now pull required row array based on _id of array         $pull: { frr_list: { _id: frr_id } } },         function(err,result){             if(result.ok==1 && result.nmodified==1 && result.n==1)                 //successfully deleted             else if(result.ok==1 && result.nmodified==0 && result.n==0)                //no record exist             else                //something goes wrong         });