$re = '/subcategory\.html\?id=([^&]*)(?:.*&)?(?:title=([^&\n]*))?/m';
$str = 'http://example.com/xyz/subcategory.html?id=3000080292&backTitle=Back&title=BabySale
http://example.com/xyz/subcategory.html?id=3000080293&title=MegaSale
http://example.com/xyz/subcategory.html?id=3000080294&backTitle=Back&';
preg_match_all($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