If you want to create subtopic with Richfaces 4 JMS push notifications, you must set a specific parameter in the message that you are sending. Specifically, suppose that you have a JMS session object (in my example I obtain it using an injection of the Seam 3 JMS module). For example, create message in this way:

@Inject
@JmsSession(transacted = false, acknowledgementMode = Session.CLIENT_ACKNOWLEDGE)
private Session session;

......

ObjectMessage message = session.createObjectMessage(notification.getNotificationObject());

Now, set string property into JMS message to define subtopic:

message.setStringProperty("rf_push_subtopic", "subTopic");

The first parameter of the setStringProperty method is a constant that Richfaces uses to get subtopic part of the JMS address. The second parameter is the subtopic address out-and-out.

Then, you can consume notification with <a4j:push> in the same way as you use TopicsContext or CDI implementation:

<a4j:push address="subtopic@topic" ondataavailable="alert(event.rf.data)"></a4j:push>