title: ldap filter to search for multiple values for an attribute
body: <p>In AD, I have multi valued attribute "departmentNumber" which may store multiple values like "dept1" and "dept2".</p>
  
  <p>I am looking for ldap filter which should retrieve the users who has more than 1 departmentnumber.</p>
  
  <p>I looked at other threads but that doesn't seems to work.</p>
  
  <p>Any help is appreciated.</p>