Region button with admin panel region selection

I want to modify my website region wise, Now it's country and city but I want to manage it Region, Country and City wise, Website Header I want to put region selection button with dropdownb menu , then select region after that that particular region countrys will be open in country panel, now only country and city there. And in admin panel I want to manage country regionwise, now only function country and city ... 01 - website home page region button with dropdown menu 02 - in Admin Panel region button Please check attached files for your reference I want to finish it today Thanks