/**
 * Допустим, новости хранятся в таблице article с полями id, title, views и year
 */
class Article extends yiibaseModel //yiidbActiveRecord
{
    // Я добавил поля в модель и наследовал yiibaseModel потому, что не работаю с бд
    public $id;
    public $title;
    public $views;
    public $year;

    public static function tableName()
    {
        return "article";
    }
}

/**
 * $articles = Article::find()
 * // Сортируем по году и ID
 * ->orderBy(['year' => SORT_DESC, 'id' => SORT_ASC])
 * // Массив будет такого вида: [2017 => [Article, Article, ....], 2018 => [...]]
 * ->indexBy('year')
 * ->all();
 */

// У меня такой таблиц нет, я просто эмулирую выборку

$articles = [
    2016 => [
        new Article([
            'id' => 1,
            'title' => "Test title",
            'views' => 100500,
            'year' => 2016
        ]),
        new Article([
            'id' => 2,
            'title' => "Test title 2",
            'views' => 1000,
            'year' => 2016
        ]),
        new Article([
            'id' => 3,
            'title' => "Title for 3",
            'views' => 200,
            'year' => 2016
        ]),
    ],
    2017 => [
        new Article([
            'id' => 4,
            'title' => "Test title 2017",
            'views' => 100500,
            'year' => 2017
        ]),
        new Article([
            'id' => 5,
            'title' => "Test title 2017 2",
            'views' => 0,
            'year' => 2017
        ]),
        new Article([
            'id' => 6,
            'title' => "Title for 2017 3",
            'views' => 800,
            'year' => 2017
        ]),
    ]
];

<div class="ThisDay-default-index">
    <div class="form-group thisday-butt">
        <div class="col-md-2">
            <button type="submit" class="btn btn-default">Далее</button>
        </div>
    </div>
    <p class="thisday-time">Выберите ключевые новости
        12 Января из прошлого:</p>
    <?php
    $form = yiiwidgetsActiveForm::begin([
        'options' => [
            'class' => 'thisday-content',
        ],
    ]); ?>
    <div class="thisday-container">
        <div class="horizontal-scroll-wrapper">
            <?php foreach ($articles as $year => $yearArticles): ?>
                <div class="control-group">
                    <h3><?= $year ?></h3>

                    <?php foreach ($yearArticles as $article): ?>

                        <?= $form->field($article, 'id[' . $year . '][]')->radio([
                            'label' => apphelpersHtml::encode($article->title)
                                . apphelpersHtml::tag('div', '', ['class' => 'control__indicator'])
                                . apphelpersHtml::tag('span', $article->views, ['class' => 'control-views-count']),
                            'labelOptions' => [
                                'encode' => false,
                                'class' => 'control control--radio',
                            ],
                        ]); ?>
                    <?php endforeach; ?>
                </div>
            <?php endforeach; ?>
        </div>
    </div>
    <?php yiiwidgetsActiveForm::end(); ?>
</div>