groupsales

<?php

$data = [
    "PO1080|2018-10-21|2",
    "PO1080|2018-10-22|1",
    "PO1102|2018-10-21|1",
    "PO1080|2018-10-25|1",
];

$res = [];

foreach ($data as $v) {
    [$sales, $date, $total] = explode('|', $v);

    if (!isset($res[$sales])) {
        $res[$sales] = [
            "sales" => $sales,
            "tanggal" => [],
            "total" => [],
        ];
    }

    $res[$sales]["tanggal"][] = $date;
    $res[$sales]["total"][] = intval($total);
}

$result = array_values($res);

echo (json_encode($result, JSON_PRETTY_PRINT));