LDAP Filter is used to as a search filter, e.g. setting LDAP filter to (|(givenName=%*)(sn=%*)) the system will use this filter when requesting entries from the LDAP server. % will be replaced with the entered prefix e.g searching on J will give the filter (|(givenName=Jo*)(sn=Jo*))resulting in a search for given name starting with a Jo or surname starting with Jo