https://kb.wpbakery.com/docs/developers-how-tos/use-param-group-in-elements/

Visual comoposer with param_group

//Backend visual composer add-on code 

vc_map(array(
  'name' => 'Accordions',
  'base' => 'maxima_accordion',
  'category' => 'Maxima',
  'params' => array(
    array(
      'type' => 'textfield',
      'name' => __('Title', 'rrf-maxima'),
      'holder' => 'div',
      'heading' => __('Title', 'rrf-maxima'),
      'param_name' => 'title',
    ),
    array(
      'type' => 'param_group',
      'param_name' => 'values',
      'params' => array(
        array(
          'type' => 'textfield',
          'name' => 'label',
          'heading' => __('Heading', 'rrf-maxima'),
          'param_name' => 'label',
        ),
        array(
          'type' => 'textarea',
          'name' => 'Content',
          'heading' => __('Content', 'rrf-maxima'),
          'param_name' => 'excerpt',
        )
      )

    ),
  ),

));


//shortcode



function maxima_accordion_shortcode($atts){
  extract(shortcode_atts(array(
    'title' => '',
    'values' => '',
  ), $atts));

  $list = '<h4>'.$title.'</h4>';


  $values = vc_param_group_parse_atts($atts['values']);

  $new_accordion_value = array();
  foreach($values as $data){
    $new_line = $data;
    $new_line['label'] = isset($new_line['label']) ? $new_line['label'] : '';
    $new_line['excerpt'] = isset($new_line['excerpt']) ? $new_line['excerpt'] : '';

    $new_accordion_value[] = $new_line;

  }

  $idd = 0;
  foreach($new_accordion_value as $accordion):
  $idd++;
    $list .=
    '<div class="panel panel-default">
				<div class="panel-heading">
					<h4 class="panel-title">
						<a class="accordion-toggle" data-toggle="collapse" data-parent="#accordion" href="#collapse'.$idd.'">
						'.$accordion['label'].'
						<span class="fa fa-plus"></span>
						</a>
					</h4>
				</div>
				<div id="collapse'.$idd.'" class="panel-collapse collapse">
					<div class="panel-body">
						<p>'.$accordion['excerpt'].'</p>
					</div>
				</div>
			</div>';

  endforeach;
  return $list;
  wp_reset_query();

}
add_shortcode('maxima_accordion', 'maxima_accordion_shortcode');