Multiple Mask Layers

How would I go about adding the second mask layer to my logo?

i.imgur com/QvWUJ.png?1

I understand that new users are not permitted to create posts containing URL's although, I believe this a simple question to answer and I may be asking it wrong.

Just to let you know that to duplicate a layer mask on a Mac, you need to press Alt/Cmd – Then drag and drop the mask to the required layer.