You can specify the visibility of layers of a PDF Underlay that is referenced PDF in a drawing.
To control the visibility of layers of an attached PDF file:
In the dialog box, the PDF Underlay list displays the name of the PDF Underlay you specified. You can select a different, previously attached PDF file from this list.
If the specified PDF Underlay is not organized by layers, the list is empty.
Access
Command: LayersPDF
Menu: Format > PDF Layer
Ribbon: Insert > Reference > Layers > PDF Underlay Layers Manager