Мое предложение, рабочий пример здесь: https://3v4l.org/W99Uu
$string = "(33.110029967689556, 35.60865999564635), (33.093492845160036, 35.63955904349791), (33.0916232355565, 35.602995170206896)";
// Split by each X/Y pair
$array = explode("), ", $string);
// Init result arrays
$arrayX = array();
$arrayY = array();
foreach($array as $pair) {
// Remove parentheses
$pair = str_replace('(', '', $pair);
$pair = str_replace(')', '', $pair);
// Split into two strings
$arrPair = explode(", ", $pair);
// Add the strings to the result arrays
$arrayX[] = $arrPair[0];
$arrayY[] = $arrPair[1];
}