Hierarchy creation in local address book

I have got a csv address book file from which i imported addresses to outlook and then from outlook to my local address book of notes.

Now i have following details for each users, (name, email address, department name)

I want to create hierarchy in this address book for different departments names so that when user creates new memo and click on view by “notes name hierarchy” he can select names from departments.

Pl. let me know is it possible? If yes how?

thanks in advance