[exim] Accepting email from certain hosts only

Hello,

I have an exim server providing email for many domains, I need exim to
accept email for some of those domains only if they come from a
certain host, for example:

example1.com -> accept email normally
example2.com -> accept email only if it comes from host
example1.another.example.com

I think this can be done using exim ACLs however, how can I make sure
that it will only affect those domains that should be affected, and
that each of those domains receive email only from its corresponding
hosts.

Thanks in advance,

JJ