Restrict People Picker search result to specific user group based on radio button value selected

Hi,

I am facing problem in restricting people picker search result to specific user group when the radio button value selected.

Ex: I have user groups called A, B and C in SharePoint 2010. And radio button has values X and Y. If I select radio button value as X then people picker search result(when I try to add person name in that field) should restrict to user group A which means I should see only User group A people names in search result. If I select radio button as Y then I should able to see all the persons names from all user group.

Please help me out to achieve this.

Thanks