I'm trying to add a domain to an Odoo V10 field for a `sale.order.line`. Specifically, I'm trying to ensure that the only Route available to choose are ones with the same name as the product related to the order line. Here is my attempt:

Here is the original out-of-the-box field definition for `route_id` on a `sale.order.line`:

     <field name="route_id" groups="sale_stock.group_route_so_lines">

I modified it to include a domain like so:

    <field name="route_id" groups="sale_stock.group_route_so_lines" domain="[('name', '=', product_id.name)]"/>

However, I seem to be unable to access the related `product.product` via the `product_id` attribute. From what I can tell, the `product_id` is simply returning the id, rather than the actual record itself. Therefore, when I try to chain the call to `name`, it doesn't work.

I get the following error when clicking into the Routes field on the order line:

    Uncaught Error: AttributeError: object has no attribute 'name'

Does anybody know the proper way to add this domain to the view?