The tm-close-all-windows message closes all additional browser window that were opened with tm-open-window.

The tm-close-window message is best generated with the ActionSendMessageWidget, which in turn is triggered by a widget such as the ButtonWidget. It is handled by the core itself.

<$button>Close All Windows
<$action-sendmessage 
  $message="tm-close-all-windows" 
/>
</$button>