add menu item to employee center

[lizijing]

I want to add a menu in the position of this it dropdown box. What should I do?
Thanks

[Michael Russ]

These menu items are maintained as Taxonomies (in the All Menu / Filter Navigator, navigate to Content Taxonomy > Taxonomies). It is a best practice to clone "Employee" the OOB base taxonomy for the Employee Center, then make your changes to the clone. This is demonstrated at about 27:00 in 

YouTube: Employee Center Academy: Migrating from Service Portal to Employee Center. I'd recommend watching this whole video.