To configure LDAP Query as a Question Type, configure your Service and choose "LDAP Query" (1) as Type and configure your Query in "Query" (2).
Here are a few examples how a Query can look like.
- Get all Users from AD: (objectclass=user)
- Get all Computers from AD: (objectclass=computer)
- Get all Members from a Group: (memberof=CN=Admins,OU=Service Users,OU=Domain,DC=techguy,DC=local)
and a lot more, feel free