<form action="{{ path('fos_user_group_edit', {'groupname': groupname} ) }}" {{ form_enctype(form) }} method="POST" class="fos_user_group_edit">
    {{ form_widget(form) }}
    <div>
        <input type="submit" value="{{ 'group.edit.submit'|trans([], 'FOSUserBundle') }}" />
    </div>
</form>
