Add Custom Taxonomies to The Events Cal Filter Bar

add-custom-taxonomies-to-tec.php

// Add custom taxonomies to Filter bar
if (class_exists('Tribe__Events__Filterbar__Filter')):
 class Tribe__Events__Filterbar__Custom extends Tribe__Events__Filterbar__Filter {
     public $type = 'select';
 
     public function get_admin_form() {
         $title = $this->get_title_field();
         $type = $this->get_multichoice_type_field();
         return $title.$type;
     }
 
     protected function get_values() {
         $terms = array();
 
         // Load all available event categories
         $source = get_terms( $this->slug, array( 'orderby' => 'name', 'order' => 'ASC' ) );
         if ( empty( $source ) || is_wp_error( $source ) ) return array();
 
         // Preprocess the terms
         foreach ( $source as $term ) {
             $terms[ (int) $term->term_id ] = $term;
             $term->parent = (int) $term->parent;
             $term->depth = 0;
             $term->children = array();
         }
 
         // Initally copy the source list of terms to our ordered list
         $ordered_terms = $terms;
 
         // Re-order!
         foreach ( $terms as $id => $term ) {
             // Skip root elements
             if ( 0 === $term->parent ) continue;
 
             // Reposition child terms within the ordered terms list
             unset( $ordered_terms[ $id ] );
             $term->depth = $terms[ $term->parent ]->depth + 1;
             $terms[ $term->parent ]->children[ $id ] = $term;
         }
 
         // Finally flatten out and return
         return $this->flattened_term_list( $ordered_terms );
     }
 
     /**
      * Flatten out the hierarchical list of event categories into a single list of values,
      * applying formatting (non-breaking spaces) to help indicate the depth of each nested
      * item.
      *
      * @param array $term_items
      * @param array $existing_list
      * @return array
      */
     protected function flattened_term_list( array $term_items, array $existing_list = null ) {
         // Pull in the existing list when called recursively
         $flat_list = is_array( $existing_list ) ? $existing_list : array();
 
         // Add each item - including nested items - to the flattened list
         foreach ( $term_items as $term ) {
             $flat_list[] = array(
                 'name'  => str_repeat( ' ', $term->depth * 2 ) . $term->name,
                 'value' => $term->term_id,
                 'data'  => array( 'slug' => $term->slug ),
                 'class' => 'tribe-events-category-' . $term->slug,
             );
 
             if ( ! empty( $term->children ) ) {
                 $child_items = $this->flattened_term_list( $term->children, $existing_list );
                 $flat_list = array_merge( $flat_list, $child_items );
             }
         }
 
         return $flat_list;
     }
 
     /**
      * This method will only be called when the user has applied the filter (during the
      * tribe_events_pre_get_posts action) and sets up the taxonomy query, respecting any
      * other taxonomy queries that might already have been setup (whether by The Events
      * Calendar, another plugin or some custom code, etc).
      *
      * @see Tribe__Events__Filterbar__Filter::pre_get_posts()
      *
      * @param WP_Query $query
      */
     protected function pre_get_posts( WP_Query $query ) {
         $new_rules      = array();
         $existing_rules = (array) $query->get( 'tax_query' );
         $values         = (array) $this->currentValue;
 
         $new_rules[] = array(
             'taxonomy' => $this->slug,
             'operator' => 'IN',
             'terms'    => $values,
         );
 
         /**
          * Controls the relationship between different taxonomy queries.
          *
          * If set to an empty value, then no attempt will be made by the additional field filter
          * to set the meta_query "relation" parameter.
          *
          * @var string $relation "AND"|"OR"
          */
         $relationship = apply_filters( 'tribe_events_filter_taxonomy_relationship', 'AND' );
 
         /**
          * If taxonomy filter meta queries should be nested and grouped together.
          *
          * The default is true in WordPress 4.1 and greater, which allows for greater flexibility
          * when combined with taxonomy queries added by other filters/other plugins.
          *
          * @var bool $group
          */
         $nest = apply_filters( 'tribe_events_filter_nest_taxonomy_queries',
             version_compare( $GLOBALS['wp_version'], '4.1', '>=' )
         );
 
         if ( $nest ) {
             $new_rules = array(
                 __CLASS__ => $new_rules,
             );
         }
 
         $tax_query = array_merge_recursive( $existing_rules, $new_rules );
 
         // Apply the relationship (we leave this late, or the recursive array merge would potentially cause duplicates)
         if ( ! empty( $relationship ) && $nest ) {
             $tax_query[ __CLASS__ ][ 'relation' ] = $relationship;
         } elseif ( ! empty( $relationship ) ) {
             $tax_query[ 'relation' ] = $relationship;
         }
 
         // Apply our new meta query rules
         $query->set( 'tax_query', $tax_query );
     }
 }

new Tribe__Events__Filterbar__Custom('Campus','campus');
new Tribe__Events__Filterbar__Custom('Department','department');

endif;

If you've created Custom Taxonomies you should be able to add this to Functions.php, replace the taxonomies I have (at the end of the snippet) with your own, and see them in the Filter Bar settings.