Follow these steps to preview your pass nodes directly in the Render View.

1. In the Hypershade, select Maya > Rendering > Render Target.

   This creates a Render Target node that you can render directly in the Render View.

2. Connect your render pass, for example, Diffuse, to your Render Target via the color and alpha attributes.
   TipYou can + drag a render pass node to a Render Target node in the Hypershade to connect them via both the color and alpha attributes.
   
3. In the Render View window, select Render Target > renderTarget1.
   
4. Click . This renders the output of the Render Target node. In this case, it is the Diffuse pass.
   

Repeat as necessary for the other render passes.