How to get to To do list with PS4 controller via Steam Link

[eatin cake]

We are using the new steam big picture mode via an Apple TV with a PS4 controller. The "Back" button (That's select/share yeah?) is used to access the todo list. Pressing it doesn't bring up anything and long pressing it brings up the new steam settings overlay.

Any ideas?

[Psymon²]

Does pushing in the touchpad part of the PS4 controller do anything?
The left half, or right half?