group field

                   array(
                        'id'              => 'group_field',
                        'type'            => 'group',
                        'title'           => 'Group Field',
                        'button_title'    => 'Add New',
                        'accordion_title' => 'Add New Field',
                        'fields'          => array(
                            array(
                                'id'         => 'text_item',
                                'type'       => 'text',
                                'title'      => 'name',
                            ),
                        ),
                    ),