Config_Container::getItem()

// will return the last directive found
$directives =& $obj->getItem('directive');

// will return the last directive found with content 'root'
$directives =& $obj->getItem('directive', null, 'root');

// will return the fourth directive with name 'bar'
$directive_bar_4 =& $obj->getItem('directive', 'bar', null, null, 4);

// will return the last section named 'foo'
$section_foo =& $obj->getItem('section', 'foo');

// will return the last section with attribute 'id' set to 'db'
$section_foo =& $obj->getItem('section', 'foo', null, array('id' => 'db'));