$re = '/(?<= AND |\, )(.*)(?= AND |$)/mU';
$str = 'NETHERLANDS (THE)
BOLIVIA (PLURINATIONAL STATE OF)
COCOS (KEELING) ISLANDS (THE)
ANTIGUA AND BARBUDA
TEST1, SOME TEXT
TEST2, SAINT HELENA AND ASCENSION AND TRISTAN DA CUNHA
TEST3, BONAIRE AND SINT EUSTATIUS AND SABA';
preg_match_all($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