$re = '/(?:LLC_BI__Stage__c[\S\s\r]*LLC_BI__Status__c|LLC_BI__Status__c[\S\s\r]*LLC_BI__Stage__c)/m';
$str = '<displayedFields>
<field>LLC_BI__Amount__c</field>
<isFieldManaged>false</isFieldManaged>
<isRequired>false</isRequired>
</displayedFields>
<displayedFields>
**<field>LLC_BI__Stage__c</field>**
<isFieldManaged>false</isFieldManaged>
<isRequired>false</isRequired>
</displayedFields>
<displayedFields>
<field>LLC_BI__lookupKey__c</field>
<isFieldManaged>false</isFieldManaged>
<isRequired>false</isRequired>
</displayedFields>
<displayedFields>
**<field>LLC_BI__Status__c</field>**
<isFieldManaged>false</isFieldManaged>
<isRequired>false</isRequired>
</displayedFields>
';
preg_match_all($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