yii\bootstrap

yii\bootstrap\ButtonDropdown

	   <?php echo yii\bootstrap\ButtonDropdown::widget([
            'label' => 'Action',
                'dropdown' => [
                    'items' => [
                        ['label' => 'DropdownA', 'url' =>  ['update', 'id' => $model->id],'options'=>['method'=>'post']],
                        ['label' => 'DropdownB', 'url' => '#'],
                    ],
                ],
            ]);
	   ?>