Your filler is still just a 4 step combo, but now you press the same button. It generates nothing, it interacts with nothing.
You have a "gauge" that just fills by existing every 10 seconds.
You spend that gauge on either the left side attack or the right side attack, each giving you a "continuation style" oGCD afterwards.
You need to do both to unlock the 3rd attack which seemingly gives you another glowing GCD follow-up.
You have an oGCD jump on a 3 stack system and 20 second cooldown that lets you ignore positionals and fills your other gauge. (And it does literally nothing until it's "full" after 3 jumps.)
That gauge lets you go into your burst, which is just Stardiver into another 4 step combo on a single button and it unlocks the PvP jump.