example interaction between a module and a common header layout in a backbone app...

header.js

App.Views.HeaderLayout = Marionette.Layout.extend({
  Controller: Marionette.Controller.extend({
    addMenu: function( menuView ) {
      this.trigger( 'menu:add', menuView );
    }
  }),
  
  menus: 0,
  
  initialize: function() {
    var controller = App.headerController = ( App.headerController || new this.Controller() );
    
    this.listenTo( controller, 'menu:add' this.drawMenu, this );
  },
  
  drawMenu: function( menuView ) {
    var $menuContainer = $( 'li', { 'class': 'dropdown' } );
    var region = this.regionManager.addRegion( 'menu' + (++this.menus), $menuContainer );
    
    region.show( menuView );
  }

});

module_initializers.js

// in an initializer for our module...

app.ModuleExample.addInitializer( function() {
  App.headerController.addMenu( new app.ModuleExample.Views.HeaderMenu() );
});

ModuleMenu.html

<a href="#projects" class="dropdown-toggle">Projects<b class="caret"></b></a>
<ul class="dropdown-menu" role="menu">
  <li><a href="#projects/myprojects">My Teams' Projects</a></li>
  <li class="divider"></li>
  <li class="nav-header">Recent Projects</li>
</ul>