95_petya_95

Если "в лоб":

1. Убираем группировку, никаких подгрупп база не выдаст, будет по 1 записи на "уровень"

- $ref_system = $pdo->prepare("SELECT * FROM `db_ref_system` GROUP BY `rs_type` ORDER BY `id` ASC");
+ $ref_system = $pdo->prepare("SELECT * FROM `db_ref_system` ORDER BY `id` ASC");

2. Фильтруем итоговый вывод в 3 массива и выводим их

<?php
$all = $ref_system->fetchAll();
$plc = array_filter($all, fn ($fields) => $fields['rs_type'] === 'plc');
$deposit = array_filter($all, fn ($fields) => $fields['rs_type'] === 'deposit');
$offer = array_filter($all, fn ($fields) => $fields['rs_type'] === 'offer');
?>
<?php foreach ([$plc, $deposit, $offer] as $level => $data): ?>
  <div class="col-md-4 col-12 mb-lg-0 mb-4">
    <div class="fw-bold h5 mb-3">
      <?= $level + 1 ?>-й уровень
    </div>
    <?php foreach($data as $ref) : ?>
    <div class="mb-4">
      <span class="text-muted fw-semibold"><?=$ref['rs_type']?></span>
      <div>
        <div class="d-flex align-items-center pt-2">
          <div class="progress w-100">
            <div class="progress-bar bg-warning" role="progressbar" style="width: 100%;" aria-valuenow="100" aria-valuemin="0" aria-valuemax="100"></div>
          </div>
          <span class="ms-3 fw-bold text-warning"><?=$ref['rs_percent']?>%</span>
        </div>
      </div>
    </div>
    <?php endforeach; ?>
  </div>
<?php endforeach; ?>