Entity Reference Selection

To 'alter' what shows in an entity reference selection

Reference https://drupal.stackexchange.com/questions/298105/can-i-create-non-default-entityreferenceselection

In src/Plugin/EntityReferenceSelection

<?php

namespace Drupal\YOUR_MODULE\Plugin\EntityReferenceSelection;

use Drupal\node\Plugin\EntityReferenceSelection\NodeSelection;

/**
 * Provides a query for a node entity reference selection.
 *
 * @EntityReferenceSelection(
 *   id = "YOUR_MODULE_REFERENCE_SELECTION_ID",
 *   label = @Translation("Filter nodes with a specific field value."),
 *   entity_types = {"node"},
 *   group = "YOUR_MODULE_REFERENCE_SELECTION_GROUP",
 *   weight = 1
 * )
 */
class YourModuleEntityReferenceSelection extends NodeSelection {
  /**
   * {@inheritdoc}
   */
  protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS') {
    $query = parent::buildEntityQuery($match, $match_operator);
    $query->condition('field_featured', 1', '=');
    return $query;
  }
}