You can use find . -name "pattern"
and then add a negative condition for the pattern you don't want to have:
find . -name "pattern_A" ! -name "pattern_B"
Example
Let's look for those files whose name contains a A
but not a B
:
$ ls -1
adfadAadsa
adfBasdA
Aksjdflksj
asdfBasdf
Badsf
$ find . -name "*A*" ! -name "*B*"
./Aksjdflksj
./adfadAadsa