I have Studio one 18.104.22.168745 Win x64
The manual says:
"14.2.7 Grouping Pads
Pads can be grouped so that when one pad in the group is triggered, the other pads in the
group will be choked, or silenced. You can add pads to one of four groups by doing the
• Select a pad you wish to assign to a Group by clicking on it.
• Click on the Group select box in the lower left corner of the pad and choose a group number.
• Repeat the process for any pad you wish to assign to a group.
Now, when a pad that is in Group 1 is triggered, all other pads in Group 1 will be silenced. This, for instance, can be used to silence different hi-hat samples, so that when a closed hi-hat
sample is played following an open hi-hat sample, the open hi-hat sample will be silenced to
prevent it from ringing through the closed hi-hat sound. This can add realism to your drum
-- but I see no Group select box anywhere.