drop down menu on main page / issue

Hello guys,

Newbie here I just learned how to modify my wordpress theme and unfortunately, I am lost…

I would like to add a drop down menu on my main page (not to the command bar).

Imagine that you have two buttons on the main page i.e. (professional) and (student). You click 1. (professional) 2. and a drop down menu is shown user can can filter his selection even more and select 3.(consultant) among (driver), (etc.). Is this doable using some plugins or should I make a PHP script? Any links,videos or advices appreciated.

Thanks a lot!

MT