code: public function getFilterSettings(\DC_Table $objDC)
      {
          $filterSettings = $this->connection->createQueryBuilder()
              ->select('f.id', 'f.name')
              ->from('tl_metamodel_filter', 'f')
              ->where('f.pid=:id')
              ->setParameter('id', $objDC->activeRecord->metamodel)
              ->execute()
              ->fetchAll(\PDO::FETCH_ASSOC);
  
          $result = [];
          foreach ($filterSettings as $filterSetting) {
              $result[$filterSetting['id']] = $filterSetting['name'];
          }
  
          // Sort the filter settings.
          asort($result);
  
          return $result;
      }
docs: Fetch all available filter settings for the current meta model.
  
  @param \DC_Table $objDC The data container calling this method.
  
  @return string[] array of all attributes as id => human name