Put hidden fields on form 2 with the values from form 1, then when page 3 kicks you back to form 2 you get all the values back from withInput().

@thaifood I already have that. but the problem is actually the

else
{
    return Redirect::back()->withInput()->with('order', $session)->withErrors($validator);
}

Because of that it gives a redirect error

return Redirect::back()->withInput()->withErrors($validator);

@Eriktisme it gives a GET request, Tho I need a POST..

Did you ever figure this out. Im facing a similar issue?

I found this, having the same problem.
First I thought to separate the two posts, inserting an information page:

1. Simple form (get)
2. Presenting the result of the post (post)
3. New page with a new post (get)
4. Result of the second post (post)

In case of error submitting page 3, laravel goes back to page 3.

Then I followed another solution:

1. Simple form (get)
2. Analyze the submitted data and if success redirect to new get page (post)
   -> New page with a new post (get)
3. Result of the second post (post)

  public function getIndex() {
    $input = Input::all();
    $validator = Validator::make($input, self::$startBooking);
    Session::put('order', $input);
    if($validator->passes()) {
      $value = Session::get('order');
      return redirect()->route('orderSummary', ['order' => $value]);
    } else {
      return Redirect::back()->withInput()->withErrors($validator);
    }