How can I create a personalized list of localities?

What is the best way to create a dropdown with diferent options based on the answer on another dropdown?

For exemple, i wanted to create a list of the localities present in each county of portugal. If someone selected in a dropdown 'Aveiro' it would only appear the localities present in 'Aveiro' and so on.

Thank you for your time.

The closest that we have is an alternative is to use a widget that behaves the same way. Have a look at the Dynamic Dropdown Widget as this closely matches your requirement.

Related guide: How-to-Add-a-Widget-to-Your-Form 

Give it a try and let us know if you'd need more help.