$re = '/(?i)\b(?:Lake|Tree)\b.*\bMan\b|\bMan\b.*\b(?:Tree|Lake)\b/';
$str = ' [0] => sth!Man!Tree!null
[1] => sth!Maning!AppTree!null
[2] => sth!Man!Lake!null
[3] => sth!Man!Tree!null
[4] => sth!Man!AppTree!null
[5] => sth!Maning!AppTree!null
[6] => sth!Man!Tree!null
[7] => sth!Maning!AppTree!null
[8] => sth!Maning!AppTree!null
[9] => sth!Man!Tree!null
[10] => sth!Man!Tree!null
[11] => sth!Man!Tree!null
[12] => sth!Man!Tree!null
[12] => sth!Man!Lake!null
[13] => sth!Maning!Tree!null';
preg_match_all($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