Magento 2 программно получает коллекцию продуктов по специальной цене

Вы можете получить товары со специальной ценой, превышающей 0, используя репозиторий товаров с критериями поиска:

/**
 * @param \Magento\Catalog\Api\ProductRepositoryInterface $productRepository
 * @param \Magento\Framework\Api\SearchCriteriaInterface $criteria
 * @param \Magento\Framework\Api\Search\FilterGroup $filterGroup
 * @param \Magento\Framework\Api\FilterBuilder $filterBuilder
 */
public function __construct(
    \Magento\Catalog\Api\ProductRepositoryInterface $productRepository,
    \Magento\Framework\Api\SearchCriteriaInterface $criteria,
    \Magento\Framework\Api\Search\FilterGroup $filterGroup,
    \Magento\Framework\Api\FilterBuilder $filterBuilder
) {
    $this->productRepository = $productRepository;
    $this->searchCriteria = $criteria;
    $this->filterGroup = $filterGroup;
    $this->filterBuilder = $filterBuilder;
}

/**
 * @throws \Magento\Framework\Exception\NoSuchEntityException
 */
public function getProductData()
{

    $this->filterGroup->setFilters([
        $this->filterBuilder
            ->setField('special_price')
            ->setConditionType('gt')
            ->setValue(0)
            ->create(),
    ]);

    $this->searchCriteria->setFilterGroups([$this->filterGroup]);
    $products = $this->productRepository->getList($this->searchCriteria);
    $productItems = $products->getItems();

    return $productItems;
}

Результат должен быть таким:

ОБНОВЛЕНИЕ:

Если вы хотите отфильтровать выбранные элементы по видимости и статусу - просто добавьте соответствующие фильтры:

/**
 * @param \Magento\Catalog\Api\ProductRepositoryInterface $productRepository
 * @param \Magento\Framework\Api\SearchCriteriaInterface $criteria
 * @param \Magento\Framework\Api\Search\FilterGroup $filterGroup
 * @param \Magento\Framework\Api\FilterBuilder $filterBuilder
 * @param \Magento\Catalog\Model\Product\Attribute\Source\Status $productStatus
 * @param \Magento\Catalog\Model\Product\Visibility $productVisibility
 */
public function __construct(
    \Magento\Catalog\Api\ProductRepositoryInterface $productRepository,
    \Magento\Framework\Api\SearchCriteriaInterface $criteria,
    \Magento\Framework\Api\Search\FilterGroup $filterGroup,
    \Magento\Framework\Api\FilterBuilder $filterBuilder,
    \Magento\Catalog\Model\Product\Attribute\Source\Status $productStatus,
    \Magento\Catalog\Model\Product\Visibility $productVisibility
) {
    $this->productRepository = $productRepository;
    $this->searchCriteria = $criteria;
    $this->filterGroup = $filterGroup;
    $this->filterBuilder = $filterBuilder;
    $this->productStatus = $productStatus;
    $this->productVisibility = $productVisibility;
}

/**
 * @return \Magento\Cms\Model\Block|null
 * @throws \Magento\Framework\Exception\NoSuchEntityException
 */
public function getProductData()
{

    $this->filterGroup->setFilters([
        $this->filterBuilder
            ->setField('special_price')
            ->setConditionType('gt')
            ->setValue(0)
            ->create(),
        $this->filterBuilder
            ->setField('status')
            ->setConditionType('in')
            ->setValue($this->productStatus->getVisibleStatusIds())
            ->create(),
        $this->filterBuilder
            ->setField('visibility')
            ->setConditionType('in')
            ->setValue($this->productVisibility->getVisibleInSiteIds())
            ->create(),
    ]);

    $this->searchCriteria->setFilterGroups([$this->filterGroup]);
    $products = $this->productRepository->getList($this->searchCriteria);
    $productItems = $products->getItems();

    return $productItems;
}