Sort of a tautological problem, no? You've chosen to serve things that are by definition served to aid digestion after a meal. I think you'll have trouble pairing them with food. My only thought would be to serve many small courses, with one digestif between each one as a sort of intermezzo. And with enough time for the flavors to dissipate before the next course.
I think the cognac would be easy to pair. Rare beef comes to mind. The others are sweet and very strongly flavored. I can only think of dessert or cheese. And for something like Chartreuse or Fernet, something plain like ice cream or cookies, maybe?
Seems very difficult.