functions.php

<?php

/* -------------------------------------------------------------------------------
 // Display the custom taxonomy term title above events list on initial load.
 ------------------------------------------------------------------------------- */

add_action('wp_enqueue_scripts', function () {
  if (! function_exists('tribe_is_event_query') || ! tribe_is_event_query()) {
    return;
  }

  $festival_name = '';
  if (isset($_GET['tribe_filterbar_eventfestival'][0])) {
    $term_id = intval($_GET['tribe_filterbar_eventfestival'][0]);
    $term    = get_term($term_id, 'event_festival');
    if ($term && ! is_wp_error($term)) {
      $festival_name = $term->name;
    }
  }

  wp_enqueue_script(
    'pf-event-festival-title',
    get_stylesheet_directory_uri() . '/assets/js/custom/event-festival-title.js',
    ['jquery'],
    '1.0',
    true
  );

  wp_localize_script('pf-event-festival-title', 'pfFestivalData', [
    'festivalName'   => $festival_name,
    'taxonomyParam'  => 'tribe_filterbar_eventfestival',
  ]);
});


/**/
/* -------------------------------------------------------------------------------
 * Include active festival title in TEC AJAX response so JS can update header after AJAX loads
 ------------------------------------------------------------------------------- */
add_filter('tribe_events_ajax_response', function ($response) {
  $response['pfFestivalTitle'] = '';

  if (isset($_REQUEST['tribe_filterbar_eventfestival'][0])) {
    $term_id = intval($_REQUEST['tribe_filterbar_eventfestival'][0]);
    $term    = get_term($term_id, 'event_festival');
    if ($term && ! is_wp_error($term)) {
      $response['pfFestivalTitle'] = $term->name;
    }
  }

  return $response;
}, 10);