When you validate your map for in royal mode you can press del before going to the next level to restart the current level.
When you do that it count like the level is validate and when you do it twice it validate the next level but you are still on the previous one.
So if you do that 5 times the map will be validate but you play only the 1st level.

Video: https://youtu.be/9SK0l6sKlQo