I would appreciate if someone could help me to create an if statement for the following scenario:
What I am after is that when a user selects a specific PRO then only the localities related to that PRO appear under the dropdown Locality. If no PRO is selected, the Locality dropdown returns all the localities.
Is this possible please?
What you're looking for are choice filters, which you'll need to use Survey123 to implement fully.
Check out this post about choice filters, as it walks you through the steps to create a cascading select, which is what you're describing.
You mean the browser-based survey format? We have a number of surveys that use cascading that we access exclusively through a browser, and they work as expected. Can you provide a screenshot of what you're seeing in your survey?