Layers Panel
The 
Layers panel provides quick access to layers
Layers List
The image below shows an example of the Layers panel of a layered PDF:
Layers with child layers will have a toggle triangle to the left of their names. Click this triangle to expand or collapse the list of child layers.
Show or Hide Layers
To show or hide a layer, click the box to the left of the layer's name to toggle its visibility. A layer with
To show or hide a parent layer and all its child layers at the same time,
To show only one layer,
Moving Layers
Click and drag a layer to move it to a new location in the layers list.
Layers Panel Toolbar
Add New Layer: Adds a new, blank layer to the PDF. The location of the new layer depends on the option selected from the menu.
- Add Before: Creates a new layer before the selected layer. If no layer is selected, the new layer is added to the top of the layers list.
- Add After; Creates a new layer after the selected layer (default). If no layer is selected, the new layer is added to the bottom of the layers list.
- Add Child: Creates a new layer as a child of the selected layer. If no layer is selected, this option is not available.
Delete Layer: Deletes the selected layer.
See Adding Layers to a PDF for more information.
Context Menu
The following options are available in the context menu of a selected layer (
Show Layer: Toggle to display or hide current layer or layers.
Isolate: Display this layer and its children, and hide all other layers.
Show All: Display all layers.
Markup Layer: Sets the selected layer as the Markup Layer. New markups will be created on this layer. The 
markup layer icon appears after the layer name.
Rename: Change the name of the layer.