Dynamic profile field, depending on previous field

LS

I'm looking for the following:

A way that a CB member can choose the biggest city in his living area, from a predefined list.

Ideally:
First select a country from a list in an input field.
Then automatically all major cities from that country are loaded in the next input field.
Next the member can choose a city from that list.

I have a feeling this could be an solution: "MySQL Field Type Plugin"
www.joomlapolis.com/cb-solutions/directory/core-enhancements/user-management/mysql-field-type-plugin

But because I do not know much about mysql, I'm not sure....

Please advice if this is possible at all.
If yes: are there solutions around, or do I need a freelancer to build this?

Patrick Roelofs

CB Conditional plugin:

www.joomlapolis.com/cb-conditional-short-review