How do I make a AJAX nested list, in AngularJS?

I've made a list who's content is loaded via AJAX, and it works as intended.

I'd now like to make each list entry load (via AJAX) and display a sublist, when clicked upon.

Is this possible in AngularJS? (I'm new to AngularJs and am more than a little confused over $scope.)

<div ng-controller="StockGroupCtrl">
  <ul>
    <li ng-repeat="group in groups">
      <span>{{group.prod_grp}}</span>
      <span>{{group.desc}}</span>
      <!-- something like
        <ul ng-controller="WhatShouldItBe?">
          <li ng-repeat="item in items">
            <span>{{item.name}}</span>
            <span>{{item.price}}</span>
          </li>
        </ul>
      -->
    </li>
  </li>
</div>

I've made the outer code work with:

function StockGroupCtrl($scope, $http) {
    $scope.groups = [];
    $scope.handleGroupsLoaded = function(data, status) {
        $scope.groups = data;
    }
    $scope.fetch = function() {
        $http.get('/api/stock/groups/').success($scope.handleGroupsLoaded);
    }
    $scope.fetch();
}

but I can't really see where to start with the inner lists.