Magento 2 - How to filter on multiselect product attribute?

Question

I want to filter multiselect product attribute which has backend type Magento\Eav\Model\Entity\Attribute\Backend\ArrayBackend. So when I save attribute it gets saved as the comma-separated values in the database. So at the time of Product filtering, I applied filter by 2 values as like this

 $this->collection->addAttributeToSelect('*');
 $this->collection->addAttributeToFilter( 'concerns', array('finset' => 'concerns_1,concerns_4'));

It's not filtering with the above code (means collection size returning zero) but when I filter on a single value its working fine. Please suggest me how can I filter on multiple values. Thanks in advance.

Answer 1

Need to pass to the addAttributeToFilter and array of arrays.

->addAttributeToFilter(
    array(
          array('attribute'=>'concerns', 'finset'=>'a'),
          array('attribute'=>'concerns', 'finset'=>'b'),
    )
);

Updated :-

->addAttributeToFilter('concerns', array('in' => $array));