Hi everyone,

I'm trying to set up two domains (site1.com and site2.com) in Next.js using the app router with route groups, but it is not working as expected.

My folder structure:

app/
  (site1)/
    page.tsx
  (site2)/
    page.tsx

And my rewrites.ts:

const rewrites = async () => {
  return [
    {
      source: "/:path*",
      has: [{ type: "host", value: "site1.com" }],
      destination: "/(site1)/:path*",
    },
    {
      source: "/:path*",
      has: [{ type: "host", value: "site2.com" }],
      destination: "/(site2)/:path*",
    },
  ];
};

export default rewrites;

### Questions:
1. Are the rewrite rules incorrect for handling multi-domain route groups?
2. Is there a recommended way to structure route groups when using domain-based routing?
3. Using a middleware for domain detection is another solution but that may become a performance issue.

Any guidance would be much appreciated! Thank you!