I would say we have to use annotations and Injection to get the bean inside another bean.
But in case you are interested to get it without using annotation you can use the following in the action/actionListener
TheBean theBean = (TheBean)FacesContext.getCurrentInstance() .getExternalContext().getRequestMap().get("theBean");
Where theBean is one we are interested to get it from being in the other bean.
That is it!