$re = '~Area="(?<Area>.*?)"(?=\]|,)~';
$str = '/MyData.csv(MemberCount.sum,Production.sum[Area="Europe "Area 1" (Germany)",Area="North America",Area="North America [Level A]"])';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php