Thanks for the suggestions! The young lady from Germany is here for a year so yes, I’ll get her a USA something but the guy from UK is now living here so I think he can gather his own local stuff. I know that when my daughter was abroad over Christmas years ago, she craved homemade items and that’s what I was thinking of for our guests.
Germans love a German breakfast, so the young lady might be delighted if you could prepare one for her – for example:
https://delishably.com/breakfast/Traditional-German-Breakfast
I was in NYC with some Germans – we had breakfast at a deli and they improvised this kind of spread – other German tourists came up to the table and congratulated us on what a great idea it had been to put it together.
If you provide a boiled egg, make sure it’s in an egg cup…
Our British friend used to always bring Terry’s chocolate oranges for my daughters. Trader Joes has their version, which I still get every year for their stockings.
I used to tell people to bring me Oreos when I lived in Germany. 
I went to Aldi’s today - what a great selection of German treats! And coincidentally, I bought that chocolate orange from TJ’s last week - I’m set! Thanks!
Excellent. Yep…Aldi has great treats…and those chocolates…yum!!