Fundamentals > Working with the Model > Layers > Layer Basics > To Create Sublayers
  
To Create Sublayers
A layer can contain a number of other layers that are considered sublayers. When a layer has been included as a sublayer, selecting the name of the top layer automatically selects the sublayers as well.
Sublayers can be associated with different layers. Thus, the sublayer can be associated with both the DETAIL layer and any other layer.
Multilevel layer structure can be created in one of two ways:
Include a layer as an item on another layer
1. Select the layer which is the sublayer from the Layer Tree and right-click Copy Item in the shortcut menu to copy the selected layer.
2. Select the layer that you want to add the sublayer and right-click Paste Item in the shortcut menu.  This adds the first layer as a sublayer to the second layer.
 
* You can also open the layer properties of the layer where you want to add the sublayer. In the Layer Properties dialog box, you can select other layers to be added to the top level layer.
* Deleting a row in the layer file by clicking and then clicking Setup File > Edit does not delete this layer from the model. However, adding a row by specifying a new layer name automatically creates a new layer with that name.