startup.cs

app.UseMvc(routes =>
{
  var shopRoutingConstraint = new RegexNamedGroupRoutingConstraint(
    "/(?<CategoryCode>[A-Z0-9]{3})_(?<ShopCode>[A-Z0-9]{3})_(?<SegmentCode>[A-Z0-9]{3})_(?<ProductId>\d+)/?$",
    "/(?<CategoryCode>[A-Z0-9]{3})_(?<ShopCode>[A-Z0-9]{3})_(?<SegmentCode>[A-Z0-9]{3})/?$",
    "/(?<CategoryCode>[A-Z0-9]{3})_(?<ShopCode>[A-Z0-9]{3})/?$",
    "/(?<CategoryCode>[A-Z0-9]{3})/?$"
  );

  routes.MapRoute
  (
    name: "nav-by-codes",
    template: "{*url}",
    constraints: new { url = shopRoutingConstraint },
    defaults: new { controller = "Shop", action = "Detail" }
  );
});