AngularJS Example:

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<div ng-app>
  <div ng-controller="GroupViewerController">
    <table class="table table-striped">
      <tr ng-repeat="a in arr" ng-controller="OneGroupViewerController">
        <td>{{a}}
          <button ng-click="change(a)">change</button>
        </td>
      </tr>
    </table>
    <div ng-controller="oneGroupItemsController">
      <input type="text" ng-model="$parent.selectedObject.test">
    </div>
  </div>
</div>

JavaScript

function GroupViewerController($scope) {
  $scope.selectedObject = {};
  $scope.selectedObject.test = "test";
  $scope.arr = ["a", "b"]
}

function OneGroupViewerController($scope) {
  $scope.change = function(a) {
    $scope.$parent.selectedObject.test = a;
  }
}

function oneGroupItemsController($scope) {

}