public ParcelEditToken BuildParcelsByRecord( 
   ParcelLayer parcelLayer,
   Guid recordGuid,
   IEnumerable<MapMember> layers
)

 try
{
  var myParcelFabricLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType<ParcelLayer>().FirstOrDefault();
  if (myParcelFabricLayer == null)
    return "Parcel layer not found in map.";

  var theActiveRecord = myParcelFabricLayer.GetActiveRecord();
  var guid = theActiveRecord.Guid;
  var editOper = new EditOperation()
  {
    Name = "Build Parcels",
    ProgressMessage = "Build Parcels...",
    ShowModalMessageAfterFailure = true,
    SelectNewFeatures = true,
    SelectModifiedFeatures = true
  };
  editOper.BuildParcelsByRecord(myParcelFabricLayer, guid);
  if (!editOper.Execute())
    return editOper.ErrorMessage;
}
catch (Exception ex)
{
  return ex.Message;
}
return "";