You can constrain the States and city dropdowns based on your users selections.
First you would need add associations from Users to State and Country. Then you can prompt your user a question for country, state, and city. When a country is selected, then the state drop down will be constrained, then when a state is selected, the city drop down can be constrained.
With a domain model like this
You can create a form like this
And then on your drop downs for States and City, you can add xpath constraints so that the list is filtered.
Then you can also take it a step further and hide the state question based on if the user has selected a country.
The same can be done with City.
Then once all that info is saved, you can display Country, state, and City per user.
Hope this helps!
what should be the data type for the dependency?
Is it enumeration or string type???