How to populate yii2 checkbox list with drop down in active forum

I have a checkbox list in my yii2 forum.

It is like this.


 <?php

             $list = ArrayHelper::map(Publisher::find()->all(),'user_id','name');

             echo $form->field($model, 'publisher_name')->widget(Select2::classname(),[

               'data' => $list,

                'options' => [

                  'multiple' => true,

                  'placeholder' => 'Choose publishers'

                ]

             ]);

            ?>

It is taking values from the database. Also, I have used for each to populate the model in the controller. Now I want to populate this checkbox list with the drop downs.

My drop downs are as follows.


<?= $form->field($model, 'country')->dropDownList(Countries::getCountries(),

                        ['id' => 'country_id', 'prompt' => 'Select  countries'])

                    ?>

And


   <?= $form->field($model, 'state')->widget(DepDrop::classname(), [

                            //'data' => Regions::getRegions($model->country),

                            'options' => ['id' => 'region_id', 'prompt' => 'Choose a country first'],

                            'pluginOptions' => [

                                'depends' => ['country_id'],

                                'placeholder' => 'Select a state',

                                'url' => Url::to(['/regions/regions'])

                            ]

                        ]) ?>

And


<?= $form->field($model, 'city')->widget(DepDrop::classname(), [

                            //'data' => Cities::getCities($model->country),

                            'options' => ['id' => 'city_id', 'prompt' => 'Select a state'],

                            'pluginOptions' => [

                                'depends' => ['country_id','region_id'],

                                'placeholder' => 'Select',

                                'url' => Url::to(['/cities/cities'])

                            ]

                        ]) ?>

And there are more drop downs whIch I will use I want to know what all are the ways i can populate the checkbox list? Are there any ways to do that?