Свой фильтр (по своим параметрам) в административной части - Joomla 3.x - Разработка расширений для Joomla 3.x

JHtmlSidebar::addFilter(
	JText::_('COM_MYWORKS_SELECT_WORK'),
	'filter_work_id',
	JHtml::_('select.options', MyworksHelper::getWorkOptions(), 'value', 'text', $this->state->get('filter.work_id'))
);

public static function getWorkOptions()
{
	$options = array();

	$db = JFactory::getDbo();
	$query = $db->getQuery(true)
		->select('id As value, name As text')
		->from('#__myworks AS a')
		->where('a.state = 1')
		->order('a.name');

	$db->setQuery($query);

	try
	{
		$options = $db->loadObjectList();
	}
	catch (RuntimeException $e)
	{
		JError::raiseWarning(500, $e->getMessage());
	}

	return $options;
}

$workId = $this->getUserStateFromRequest($this->context . '.filter.work_id', 'filter_work_id');
$this->setState('filter.work_id', $workId);

$id .= ':' . $this->getState('filter.work_id');

// Filter by work
$workId = $this->getState('filter.work_id');

if (is_numeric($workId))
{
	$query->where('a.workid = ' . (int) $workId);
}

JHtmlSidebar::addFilter(
	JText::_('COM_MYWORKS_SELECT_WORK'),
	// filter[work_id], а не filter_work_id
	'filter[work_id]',
	JHtml::_('select.options', MyworksHelper::getWorkOptions(), 'value', 'text', $this->state->get('filter.work_id'))
);