Allows you to wrap a section of fields on a Gravity Form in a CSS class

gravityform-sections.php

//* Format specific sections in a Gravity Form - code based on
// http://www.jordancrown.com/multi-column-gravity-forms/ and https://sridharkatakam.com/splitting-gravity-forms-fields-into-2-columns/
function gform_format_sections( $content, $field, $value, $lead_id, $form_id ) {
  if( !IS_ADMIN ) { // only perform on the front end

    // target section breaks
    if( $field['type'] == 'section' ) {
      $form = RGFormsModel::get_form_meta( $form_id, true );

      // check for the presence of formatted section class
      $form_class = explode( ' ', $form['cssClass'] );
      $form_class_matches = array_intersect( $form_class, array( 'formatted-sections' ) );

      // check for the presence of specific classes in sections
      $field_class = explode( ' ', $field['cssClass'] );
      $field_class_matches = array_intersect( $field_class, array('student-1', 'student-2', 'student-3', 'student-4', 'student-5', 'end-format') );

      // if field is a formatted section, perform the list split
      if( !empty( $form_class_matches ) && !empty( $field_class_matches ) ) { // make sure to target only multi-column forms

        // retrieve the form's field list classes for consistency
        $form = RGFormsModel::add_default_properties( $form );
        $description_class = rgar( $form, 'descriptionPlacement' ) == 'above' ? 'description_above' : 'description_below';

        // close current field's li and ul and begin a new list with the same form field list classes
        return '</li></ul><ul class="gform_fields '.$form['labelPlacement'].' '.$description_class.' '.$field['cssClass'].'"><li class="gfield gsection empty">';

      }
    }
  }

  return $content;
}
add_filter( 'gform_field_content', 'gform_format_sections', 10, 5 );