I need to collect address data from people via a form. They will select data from three combo-boxes which shows country, city and district lists.

Each combo-box will filter the next one. When user select a country, he’ll see only the selected country’s cities, and when he select a city, he’ll see only selected city’s districts. If a country is not selected, he won’t see cities and districts, and if a city is not selected, he won’t see districts.

How can I do this easily? Do you know a useful plugin for my need? Any help would be appreciated.

Regards.

and Gravity Forms, too: https://www.gravityforms.com/add-ons/chained-selects/

This tutorial shows how to do it with the free Contact Forms 7: https://bdwm.be/how-to-create-dynamically-populated-cascading-dropdown-lists-for-contact-form-7/