Have an instance of \Magento\Catalog\Mode\ResourceModel\Product
as a dependency for your class and call methods from that class.
/**
* @var \Magento\Catalog\Mode\ResourceModel\Product
*/
private $productResource;
public function __construct(
....
\Magento\Catalog\Mode\ResourceModel\Product $productResource,
....
) {
....
$this->productResource = $productResource;
....
}
now, in the methods where you need the value, let's say $_product
is the product instance you can do this:
$seedBank = $this->productResource()->getAttribute('brand')->getFrontend()->getValue($_product);