is there a way to open all folders all at once?
In the Project window, you can Ctrl/Cmd + click to the folder icon in the track list. Then all folders are collapsed or expanded. Unfortunately this doesn’t work in the Visibility area.
You can make a Project Logical Editor preset:
Container Type is | Equal | FolderTrack
Track Operation | Folder | Open
You can assign a KeyCommand to this preset.
Or, yo can use native Cubase function
Project > Track Folding > Unfold Tracks
yes I know that all, thank you, but originally I was meaning the white rectangles in the left zone of the mixer. but as far as I tested there is no way.
Unfortunately, no way over the triangles in the MixCosnole (or even Project window) Inspector Visibility tabs.