Really tricky to learn at first but these cues should help. Also recommended to hold grab the whole time.
After transition, wavedash and bhop off the 1st platform.

You need to line up Madeline to the platforms before performing an extended super and a demohyper respectively.
After the super, line yourself up then do an extended demohyper into a buffered upright dash.
Hold jump and cb with 2nd jump button. During transition, let go of jump and cb after transition.