The department as seen by Attendant Console is just a list of people who have that particular string listed as their Department in LDAP. If you configure at least one person as belonging to a certain department in DC Directory or in your AD or Netscape integrated directory, it should be searchable in Attendant Console.
If you are using the CallManager built-in DC Directory, you can set any user's Department using the Global Directory function in CCMAdmin. If you are integrated with Active Directory, you need to set the Department attribute on the user using Active Directory Users & Computers. I'm not sure how it works with the Netscape LDAP directory, but you probably don't have that.
