If your holiday includes Paris, Lyon and Nice, the cleanest proof of accommodation is a separate, genuine hotel reservation for each overnight stop, with dates that connect without unexplained gaps. You do not need to pretend the entire trip happens in one city. You need a simple timeline showing where you plan to sleep on each night, supported by confirmations that match the travelers and dates in your itinerary.
Consider a ten-night French holiday. You land in Paris on June 5, take the train to Lyon on June 9, continue to Nice on June 12 and fly home on June 15. The accommodation plan almost writes itself: Paris June 5–9, Lyon June 9–12 and Nice June 12–15. Each check-out date is the next hotel's check-in date. Anyone reading the file can understand the trip in seconds.