Magento 2 product collection not filtering by custom attribute (Type multi-select)?

Question

I am trying to filter product collection with custom attribute "Groups" code "group" which is a multi-select attribute created from Magento admin, but it is giving empty result (this attribute is assigned to products)

Code:

$collection = $objectManager->create('Magento\Catalog\Model\ResourceModel\Product\Collection');
        $collection->addAttributeToSelect('*');
        $collection->addAttributeToFilter('group', array( 'in' => array( 5 ) ));
        //$collection->addAttributeToFilter(array( array('attribute'=>'group', 'eq' => '5')));
        $collection->load();

what am I doing wrong ?

Note: Excuse me for using Object manager as currently I am just trying functionality

Answer 1

Finally got the solution

$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
/** @var \Magento\Catalog\Model\ResourceModel\Product\Collection $productCollection */
$collection = $objectManager->create('Magento\Catalog\Model\ResourceModel\Product\Collection');
$collection->addAttributeToSelect('*');
$collection->addFieldToFilter('group',
    array(
        array('finset'=> array(5))
    )
);
$collection->load();

used addFieldToFilterinstead of addAttributeToFilter

$collection->addFieldToFilter('group',
        array(
            array('finset'=> array(5))
        )
    );