FrontendUser::getGroups() 

\nn\t3::FrontendUser()->getGroups($returnRowData = false); 

Get user groups of the current FE user. Alias to \nn\t3::FrontendUser()->getCurrentUserGroups();

// only load title, uid and pid of the groups
\nn\t3::FrontendUser()->getGroups();
// load complete data set of the groups
\nn\t3::FrontendUser()->getGroups( true );

| @return array

public function getGroups( $returnRowData = false )
{
	return $this->getCurrentUserGroups( $returnRowData );
}