$re = '/"Id":"(?<campid>.*?)","Status":"(?<status>.*?)","Five9__Five9list__c":"(?<five9list>.*?)"}]}/m';
$str = '{"searchRecords":[{"attributes":{"type":"Campaign","url":"/services/data/v43.0/sobjects/Campaign/701C0000000sVOVIA2"},"Id":"701C0000000sVOVIA2","Status":"Planned","Five9__Five9list__c":"Toast_list_outbound"}]}';
preg_match_all($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