That’s a good question. I don’t think there’s a general “tool” for making beat maps for all kinds of rhythm / music-based games. The closest thing to that would be creating a MIDI for a song you like– at least then, you have a reference for beat maps in general.
That’s not what I did. I had the sheet music of the songs Cityfires composed, and then translated the melodies (with a creative license) into arrays.