Image occlusion (hide all / show all)

Hi all!

I saw this was a feature added last year that you can toggle hiding all the other occlusions in a card except the one that is being tested specifically on the card.

I saw the shortcut used to be ALT T and there used to be a button for it, however I cannot see this at all, any idea what this is?

Thanks!

Click on preview. The button is there