I can't find the description for the "Ceremonial Focus" proficiency in the Heroic Companion. It's not listed among the New Proficiencies, and a search of the draft document doesn't yield any description.
I think it's what Personal Talisman used to be called since Personal Talisman isn't on any of the proficiency lists.
It's a holdover from an earlier version of the ceremonial system - allowed a ceremonialist to 'specialize' in a ceremony. The mechanics don't really translate to the current system.
It's been eliminated and replaced with Personal Talisman.