restricting acls more by adding a filter

I have a ldapsearch that returns this object

sendmailMTAClassName: w sendmailMTAClassValue: xxx sendmailMTAClassValue: yyy sendmailMTAClassValue: zzz objectClass: sendmailMTA objectClass: sendmailMTAClass

I thought I could strengthen the acl by just appending to with a filter

but if I add these below, the ldapsearch does not return anything err=32

filter=(objectClass=sendmailMTAClass) filter=(|(objectClass=sendmailMTAClass)(objectClass=sendmailMTA)) filter=(|(objectClass=sendmailMTAClass)(objectClass=sendmailMTA)) filter=(objectClass=sendmailMTA*)

If I change the filter to this, I get the expected result again

filter=(objectClass=*)

Goal is to have ldapsearch only list the specific objectClasses. Or should I do this with listing only attributes.