Hi, I'll have to ask to be sure I understand your question.
You need the hours (planned /expected or actual?) on the bars of the Gantt chart
or on a Netplan > Organisational Chart (showing the WBS chart of the project)?
Total hours (again planned/expected or actual?) of a grouped work...
By groups you mean activities with sub-activities?
Or when the Groupings feature is enabled?
Best regards, Vicky