you've to master 3 Challenges on one track. I choosed the first event "Greenhorns Grove" and the first track called "Turbine Tower"
Challenge 1: Slick Flipping (0:07)
here you've to perform 10 flips (front or backwards) or more in a zero fault run
Challenge 2: Nice and Calm (1:05)
here you've to push the hidden button to stop all the turbines. on the second ramp jump from the bike (hit the Y button) to reach the hook
Challenge 3: Unyielding 1 (1:25)
i think this is the hardest challenge on this track. you've to do a zero fault run without leaning. you may only push the R2 and L2 buttons. this could be a littlebit tricky
good luck :)