From my magento2 backend i created 2 website. 1st default website xxxx.com 2nd website is yyyy.com. 
In my sales order email template, added

```
$_order = $_item->getOrder();
$_objectManager = \Magento\Framework\App\ObjectManager::getInstance();

$product = $_objectManager->get('Magento\Catalog\Model\Product')->load($_item->getProductId());
echo $product->getProductUrl();

```

When i place order from 2nd website (i.e.,) yyyy.com, product Base URL getting xxxx.com

Please let me know how to get base URL for multiwebsite sales email template.