Bug 128293 [Contributions] visible/enabled: Object contributions contributed to submenus do not show up
bundles/org.eclipse.jface/src/org/eclipse/jface/action/SubMenuManager.java
String rest = null;
        int separator = path.indexOf('/');
        if (separator != -1) {
            id = path.substring(0, separator);
            rest = path.substring(separator + 1);
        }
        IContributionItem item = find(id); 
        if (rest != null && item instanceof IMenuManager) {
            IMenuManager menu = (IMenuManager) item;
            item = menu.findUsingPath(rest);
        }
        return item;
    }
    /* (non-Javadoc)
     * @see org.eclipse.jface.action.IContributionItem#getId()
     */
    public String getId() {
        return getParentMenuManager().getId();
    }
    /**
     * Returns the parent menu manager that this sub-manager contributes to.
     */
    protected final IMenuManager getParentMenuManager() {
        
        
        return (IMenuManager) getParent();
    }
    /* (non-Javadoc)
     * @see org.eclipse.jface.action.IMenuManager#getRemoveAllWhenShown()
     */