优化Yii2 Select2多选框：处理重复数据项显示问题

$allStaffsGroupOffice = [
    "main office" => [
        2 => "123 123"
    ],
    "office 1" => [
        3 => "staff_1",
        6 => "staff_2",
        2 => "123 123" // 重复项
    ],
    "office 3" => [
        4 => "staff_3",
        3 => "staff_1"
    ],
    "office 2" => [
        5 => "staff_4",
        3 => "staff_1"
    ]
];

// 假设这是从 Tasks::getAllStaffsGroupOffice() 获取的原始数据
$allStaffsGroupOffice = [
    "main office" => [
        2 => "123 123"
    ],
    "office 1" => [
        3 => "staff_1",
        6 => "staff_2",
        2 => "123 123"
    ],
    "office 3" => [
        4 => "staff_3",
        3 => "staff_1"
    ],
    "office 2" => [
        5 => "staff_4",
        3 => "staff_1"
    ]
];

$repeatedStaff = []; // 用于记录已处理的员工ID
$newUniqueList = []; // 存储去重后的新数据

foreach ($allStaffsGroupOffice as $officeName => $staffList) {
    foreach ($staffList as $staffId => $staffName) {
        // 如果该员工ID尚未被添加到去重列表中
        if (!in_array($staffId, $repeatedStaff)) {
            // 记录该员工ID，表示已处理
            $repeatedStaff[] = $staffId;
            // 将该员工添加到新列表中，并保留其办公室分组
            $newUniqueList[$officeName][$staffId] = $staffName;
        }
    }
}

// $newUniqueList 现在包含去重后的员工列表，并保持了办公室分组
/*
$newUniqueList 的示例输出：
array:4 [▼
  "main office" => array:1 [▼
    2 => "123 123"
  ]
  "office 1" => array:2 [▼
    3 => "staff_1"
    6 => "staff_2"
  ]
  "office 3" => array:1 [▼
    4 => "staff_3"
  ]
  "office 2" => array:1 [▼
    5 => "staff_4"
  ]
]
*/

use kartik\select2\Select2;
use yii\helpers\ArrayHelper;
use Yii;

// ... 前面处理 $allStaffsGroupOffice 得到 $newUniqueList ...

return $this->form->field($this->model, 'observers')
            ->widget(Select2::className(),
                [
                    'data' => $newUniqueList, // 使用去重后的数据
                    'disabled' => !$this->can['changeObservers'],
                    'options' => [
                        'multiple' => true,
                        // 确保 'value' 属性也使用去重后的员工ID列表
                        'value' => ArrayHelper::map($this->model->observers, 'staff_id', 'staff_id'),
                        'placeholder' => Yii::t('tasks_forms', 'FORM_PLACEHOLDER_CHOOSE'),
                        'class' => 'hiddenInput'
                    ],
                    'pluginOptions' => [
                        'allowClear' => true,
                        'closeOnSelect'=> false,
                    ],
                    'pluginLoading' => false,
                ]);