Those hidden menus were never designed for customer use. Roku has always reserved the ability to alter or remove functions from them. Sometimes they get moved to the "normal" menus, but often they are removed. I don't believe this is something that has been moved to the settings menu, so it likely is no longer available.
Nvidia Shield, Roku Stick (3600), Ultra (4640), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.