URL Maintenance Page irule

I still do not exactly understand what you are planning to do, but generally speaking, it is possible to create an iRule that takes the URI and the host header into account. Taking your example above, the host would be "www.google.com" and the URI would be "/shop/x1". You can do with that whatever you like, e.g.:

when HTTP_REQUEST {
  if { [HTTP::uri] starts_with "/shop/x1" } {
    HTTP::respond 200 content {  }
  }
}

or

when HTTP_REQUEST {
  if { [string tolower [HTTP::host]] starts_with "www.google.com" } {
    HTTP::respond 200 content {  }
  }
}

Is that what you meant??