Dynamic Dropdown from CSV or database

How can I use dynamic dropdown populated from a CSV or DB?

I have a column for list A and a second column for list B.
Dropdown from list B should be populated according to selection from list A.
Source file is CSV inside root, or inside same database table.

Thank you!

Hello Kai. The absolutely easiest way to do this is with the paid plugin Populate Anything from Gravity Wiz:

I recommend contacting them to see if your scenario is covered by their plugin.

Because you are populating list B dependent on the choice made in list A, it sound like you would be a candidate for our Chained Selects Add-On: Chained Selects Add-On for WordPress Forms | Gravity Forms

That add-on is available with an Elite license.

If you have any other questions, please let us know.