public Topology GetTopology()

//Note: Call within QueuedTask.Run()
//Get the Topology of another Topology layer
var existingTopology = MapView.Active.Map.GetLayersAsFlattenedList().OfType<TopologyLayer>().FirstOrDefault();
if (existingTopology != null)
{
  var topology = existingTopology.GetTopology();
  //Configure the settings for a new Catalog layer using the CatalogDataset of an existing layer
  var topologyLyrParams = new TopologyLayerCreationParams(topology);
  topologyLyrParams.Name = "NewTopologyLayerFromAnotherTopologyLayer";
  topologyLyrParams.AddAssociatedLayers = true;
  LayerFactory.Instance.CreateLayer<TopologyLayer>(topologyLyrParams, MapView.Active.Map);
}