How to display drop down based on another dropdown

Hi  I have three drop down country,state,city. I want to implement a scenario, when country is changed then corresponding state will display on state dropdown and when state is selected then corresponding  city will display on city dropdown.I read it about the onchange event but not able to use it for scenerio. Domain Model Page View   Reference Selector   Please suggest,how i will implement scenario .
1 answers

You can use restraints for the selectors. Please review the following part from the reference guide.