They did not answer this, so I decided to continue and show how to do it. Unfortunately, for some reason, the attempt in the question did not work, but what you can do is reference the function between the curly braces and return a line of the desired representation. For example, the controller would look like this:
$scope.groups = ['main','cases', 'models'];
$scope.pickView = function(index){
return $scope.groups[index];
};