HTTP Remote and Previewing live layers

When adding layer variants to a remote button from the provided Basketball Scorekeeper and countdown clock layers, included in the pre programmed group of buttons there is a live previews of the layers outputs.
I have variations of these layers, but I do not have available to select a group of variants or I can not set up an individual button to be a live layer preview.
Is this something that needs to be set up in the layer in QC that I am overlooking? Or is there some other component and place to make this happen? Any explanation, clues or guidance to be pointed in the right direction to make this happen would be greatly appreciated,