Limit data fields to a single entry?


I’m currently setting up our icinga2 infrastructure from the ground up to replace our old icinga/adagios setup.

I’ve made a lot of progress but I’m stumped at how to limit a user to only be able to choose a single entry from a data field that has a datalist type.

ie: I have a data field called “device environment” and a datalist with keys “production” and “development”
I would like have my hosts template only accept one or the other of those 2 entries, is that possible? if so, how can I achieve this?