Registration form: dynamic select field

[tofrou]

Hello,

I'm using Prestashop 1.7

I've added fields to subscription form with hook additionalCustomerFormFields and I'm looking to bind a text field to a select field 

To be clear, customer enter his code in a field then select field display an option list according to his code

I have a vague idea of how I should do it. (jquery, ajax, ...)
In terms of code I have the impression that FormFields are not designed to handle this type of behavior

Would you mind a site doing the same thing?
 

Thanks