EMD AD/LDAP addon allows importing users belonging to certain groups configured in base DN. If you're using Active Directory, your groups must be in "objectCategory=group". If you're using Open LDAP, the groups can be any of the following:
If you do not see the groups that you want to be imported, it means either your Base DN is not correct or the groups are not configured properly in Active Directory or LDAP server. Base DN (e.g. "dc=domain,dc=tld") is the top level of the AD/LDAP directory tree. Base DN is used to define the highest level of the AD/LDAP search scope where your groups are configured. You can check if your configuration is correct using any LDAP browser after binding to your base DN.