AngularJS Example:

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<body ng-app="myapp">
    <div ng-controller="outer1">
          <div ng-controller="inner1">
          </div>
          <div ng-controller="inner2">
          </div>
    </div>
    <div ng-controller="outer2">
    </div>
 </body>

JavaScript

var app = angular.module("myapp", []);

app.controller("outer1", function($scope) {
	$scope.$on("newmessage", function() {
			console.log("outer1");
	});
	$scope.$broadcast("newmessage");
});

app.controller("inner1", function($scope) {
	$scope.$on("newmessage", function() {
			console.log("inner1");
	});
});

app.controller("inner2", function($scope) {
	$scope.$on("newmessage", function() {
			console.log("inner2");
	});
});

app.controller("outer2", function($scope) {
	$scope.$on("newmessage", function() {
			console.log("outer2");
	});
});