public DefinitionQuery DefinitionQuery {get; set;}

//Note: Call within QueuedTask.Run()
var createParams = new CatalogLayerCreationParams(new Uri(@"C:\CatalogLayer\CatalogDS.gdb\HurricaneCatalogDS"));
//Set the definition query
createParams.DefinitionQuery = new DefinitionQuery("Query1", "cd_itemname = 'PuertoRico'");
//Set name of the new Catalog Layer
createParams.Name = "PuertoRico";
//Create Layer
var catalogLayer = LayerFactory.Instance.CreateLayer<CatalogLayer>(createParams, MapView.Active.Map);

//Note: Call within QueuedTask.Run()
//Get the CatalogDataset of another Catalog layer
var existingCatalogLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType<CatalogLayer>().FirstOrDefault();
if (existingCatalogLayer != null)
{
  var catalogDataset = existingCatalogLayer.GetCatalogDataset();
  //Configure the settings for a new Catalog layer using the CatalogDataset of an existing layer
  var catalogLyrParams = new CatalogLayerCreationParams(catalogDataset);
  catalogLyrParams.Name = "NewCatalogLayerFromAnotherCatalogLayer";
  catalogLyrParams.DefinitionQuery = new DefinitionQuery("Query1", "cd_itemname = 'Asia'");
  LayerFactory.Instance.CreateLayer<CatalogLayer>(catalogLyrParams, MapView.Active.Map);
}