jQuery(document).ready(function() {
jQuery('.repeatable-add').click(function() {
    $(this).parent().append('<ul id="custom_branding-repeatable1" class="custom_repeatable_sub ui-sortable"></ul>');
    //alert(jQuery(this).closest('td').find('ul').attr('id'));
    field = jQuery(this).parent().find('li:last').clone(true);
    fieldLocation = jQuery(this).parent().find('li:last');
    console.log(field);
    jQuery('input', field).val('').attr('name', function(index, name) {
        return name.replace(/(d+)/, function(fullMatch, n) {
            //alert(Number(n) + 1)
            return Number(n) + 1;
        });
    })
    field.insertAfter(fieldLocation, jQuery(this).closest('td'))
    return false;
});

jQuery('.repeatable-remove').click(function(){
    jQuery(this).parent().remove();
    return false;
});

jQuery('.custom_repeatable').sortable({
    opacity: 0.6,
    revert: true,
    cursor: 'move',
    handle: '.sort'
});


/*---- Sub Add---*/
jQuery('.repeatable-add-sub').click(function() {

    //alert(jQuery(this).closest('ul').attr('class'));
    field_sub = jQuery(this).parent().find('.custom_repeatable_sub li:last').clone(true);
    fieldLocation_sub = jQuery(this).parent().find('.custom_repeatable_sub li:last');
    console.log(field_sub);
    jQuery('input', field_sub).val('').attr('name', function(index, name) {
        return name.replace(/(d+)/, function(fullMatch, n) {
            return Number(n) + 1;
        });
    })
    field_sub.insertAfter(fieldLocation_sub, jQuery(this).closest('td'))
    return false;
});
 <?php

// Field Array
$prefix = 'custom_';
$custom_meta_fields = array(
array(
 'label' => 'Branding & Identity',
 'desc'  => 'A description for the field.',
 'id'    => $prefix.'branding',
 'type'  => 'repeatable'
 )

);
// The Callback
function show_custom_meta_box() {
global $custom_meta_fields, $post;
// Use nonce for verification
echo '<input type="hidden" name="custom_meta_box_nonce" value="'.wp_create_nonce(basename(__FILE__)).'" />';

// Begin the field table and loop
echo '<table class="form-table">';
foreach ($custom_meta_fields as $field) {
    // get value of this field if it exists for this post
    $meta = get_post_meta($post->ID, $field['id'], true);
    // begin a table row with
    echo '<tr>
            <td><strong><label for="'.$field['id'].'">'.$field['label'].'</label></strong>&nbsp;';
            switch($field['type']) {
                // text
 case 'text':
     echo '<input type="text" name="'.$field['id'].'" id="'.$field['id'].'" value="'.$meta.'" size="30" />
         <br /><span class="description">'.$field['desc'].'</span>';
 break;
 // repeatable
 case 'repeatable':
     echo '
             <ul id="'.$field['id'].'-repeatable" class="custom_repeatable"><a class="repeatable-add button" href="#">+</a>';
     $i = 1;
     if ($meta) {
         foreach($meta as $row) {
             echo '<li class="nthNumeber-'.$i.'"><span class="sort hndle">|||</span>
                         <input type="text" name="'.$field['id'].'['.$i.']" id="'.$field['id'].'" value="'.$row.'" size="30" />
                         <a class="repeatable-remove button" href="#">-</a>';
                         echo '<ul id="'.$field['id'].'-repeatable'.$i.'" class="custom_repeatable_sub">';
          $j = 1;
          if ($meta) {
              foreach($meta as $row) {
                  echo '<li class="nestedNumeber-'.$j.'"><span class="sort hndle">X</span>
                              <input type="text" name="'.$field['id'].$i.'['.$j.']" id="'.$field['id'].'" value="'.$row.'" size="30" />
                              <a class="repeatable-remove button" href="#">-</a></li>';
                  $j++;
              }
          } else {
              echo '<li><span class="sort hndle">x</span>
                          <input type="text" name="'.$field['id'].$i.'['.$j.']" id="'.$field['id'].'" value="" size="30" />
                          <a class="repeatable-remove button" href="#">-</a></li>';
          }
          echo '<a class="repeatable-add-sub button" href="#">Add NEW</a>';
          echo '</ul>';

             echo '</li>';
             $i++;
         }
     } else {
         echo '<li class="nthNumeber-'.$i.'"><span class="sort hndle">|||</span>
                     <input type="text" name="'.$field['id'].'['.$i.']" id="'.$field['id'].'" value="" size="30" />
                     <a class="repeatable-remove button" href="#">-</a></li>';
         echo '<ul id="'.$field['id'].'-repeatable'.$i.'" class="custom_repeatable_sub">';
          $j = 1;
          if ($meta) {
              foreach($meta as $row) {
                  echo '<li class="nestedNumeber-'.$j.'"><span class="sort hndle">X</span>
                              <input type="text" name="'.$field['id'].$i.'['.$j.']" id="'.$field['id'].'" value="'.$row.'" size="30" />
                              <a class="repeatable-remove button" href="#">-</a></li>';
                  $j++;
              }
          } else {
              echo '<li class="nestedNumeber-'.$j.'"><span class="sort hndle">x</span>
                          <input type="text" name="'.$field['id'].$i.'['.$j.']" id="'.$field['id'].'" value="" size="30" />
                          <a class="repeatable-remove button" href="#">-</a></li>';
          }
          echo '<a class="repeatable-add-sub button" href="#">Add NEW</a>';
          echo '</ul>';

     }
     echo '</ul>
         <span class="description">'.$field['desc'].'</span>';
 break;
            } //end switch
    echo '</td></tr>';
} // end foreach
echo '</table>'; // end table
}

// Save the Data
function save_custom_meta($post_id) {
global $custom_meta_fields;

// verify nonce
if (!wp_verify_nonce($_POST['custom_meta_box_nonce'], basename(__FILE__)))
    return $post_id;
// check autosave
if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE)
    return $post_id;
// check permissions
if ('page' == $_POST['post_type']) {
    if (!current_user_can('edit_page', $post_id))
        return $post_id;
    } elseif (!current_user_can('edit_post', $post_id)) {
        return $post_id;
}

// loop through fields and save the data
foreach ($custom_meta_fields as $field) {
    $old = get_post_meta($post_id, $field['id'], true);
    $new = $_POST[$field['id']];
    if ($new && $new != $old) {
        update_post_meta($post_id, $field['id'], $new);
    } elseif ('' == $new && $old) {
        delete_post_meta($post_id, $field['id'], $old);
    }
} // end foreach
}
add_action('save_post', 'save_custom_meta');

?>
jQuery('.repeatable-remove-sub').click(function(){
    jQuery(this).parent().remove();
    return false;
});

jQuery('.custom_repeatable_sub').sortable({
    opacity: 0.6,
    revert: true,
    cursor: 'move',
    handle: '.sort'
});
});