$re = '~^(?:[^-]*-){2}\s*\K[^/]+~m';
$str = 'a - bc/def_g - A/mn/us/ww
opq - rs/ts_uf - BC/wx/yza
Abc - so/dhie7u - XYZ/En/xy/jkq - QWNE';
preg_match_all($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