Can you put more than one xmas cactus in a pot?

Question

I have 3 small–wanted to combine them in a bigger pot

Answer 1

Certainly, just make sure the pot fits them adequately with a bit of room too grow. They do like to have their roots snug; so not too large of a container.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/christmas-cactus/repotting-christmas-cactus.htm