The next js docs detail how to create middleware on page calls.

Then, create a _middleware.ts file under your /pages directory.

Finally, export a middleware function from the _middleware.ts file.

// pages/_middleware.ts

import type { NextFetchEvent, NextRequest } from 'next/server'

export function middleware(req: NextRequest, ev: NextFetchEvent) {
  return new Response('Hello, world!')
}

how do we chain multiple middleware functions at a specifc level in page hierarchy?

Or is this designed so that each level has one middleware file and function?