As far as I know , that button has been eliminated in 2026.
It's still possible to edit unwanted audio in the audio edit view.
This can be done by cutting the unwanted audio or using the envelope volume.

Last edited by jpettit; 7 hours ago.

Studio One (latest version), Win 11 23H2 , i9 -10940X 3.3 GHz, 32GB Mem, a 4K 40" monitor, PreSonus Studio Live III Console as interface/controller. secondarily test on Reaper, Cakewalk, and S1 on Surface Pro 3 Win 10 (latest versions).