To Manually do this for appointment(s) sent to your Groupwise:
1 - right-click or open appointment in Groupwise, select Delegate and put the recipient your Google account you wish to share with Once email is in your Google account of your choice, click Add to Google Calendar.
To Automate doing this for appointment(s) send to your Groupwise:
1 . From GroupWise, create a rule like this:
“When event is Filed to Calendar folder and if condition is Appointment, Add Action to Delegate to: email@example.com Comments to recepient:GWDelgate”
2 . From gmail, create a filter where the search criteria is from your GroupWise email address, firstname.lastname@example.org, and has the words GWDelegate.
3 . Set the action to “Delete it”.
Note: Some step may change as updates come about but the general steps are here.