I find a way. Maybe it will help somebody.
public function exportAction(Request $request)
{
$what = Array('telephone','email');
$format = $request->get('format');
$allowedExportFormats = (array) $this->admin->getExportFormats();
if(!in_array($format, $allowedExportFormats) ) {
throw new \RuntimeException(sprintf('Export in format `%s` is not allowed for class: `%s`. Allowed formats are: `%s`', $format, $this->admin->getClass(), implode(', ', $allowedExportFormats)));
}
$filename = sprintf('export_%s_%s.%s',
strtolower(substr($this->admin->getClass(), strripos($this->admin->getClass(), '\\') + 1)),
date('Y_m_d_H_i_s', strtotime('now')),
$format
);
$datagrid = $this->admin->getDatagrid();
$datagrid->buildPager();
$flick = $this->admin->getModelManager()->getDataSourceIterator($datagrid, $what);
return $this->get('sonata.admin.exporter')->getResponse($format, $filename, $flick);