Do you want to change email address recepient in Woocommerce email notification for Completed Order and for specific product?

From your function.php file or Custom plugin, add this snippet

 add_filter( 'woocommerce_email_recipient_customer_completed_order', 'your_email_recipient_filter_function', 10, 2);

function your_email_recipient_filter_function($recipient, $object) {
global $woocommerce, $post;
$order = new WC_Order($post->ID);
$order_data = $order->get_data();

$items = $order->get_items();
foreach ( $items as $item ) {
    $product_id = $item['product_id'];
    
    if($product_id === 10059){
        $recipient = ' test@test.com';

    }
}

    return $recipient;
}

This is not also limited to completed orders, you can also change the filter function to other Woocommerce statuses

woocommerce_order_status_pending
woocommerce_order_status_failed
woocommerce_order_status_on-hold
woocommerce_order_status_processing
woocommerce_order_status_completed
woocommerce_order_status_refunded
woocommerce_order_status_cancelled

I also use this as reference for accomplishing this simple code: Woocommerce Detecting Completed Order Completion