Display the footprint of multiple scenarios and the event as a whole

Use case: A seminar may be divided into two parts, with the first part dedicated to directors and the second part bringing together all participants.

Requirement: For a single event, it would be useful to display the carbon footprint of the first part (scenario 1), the second part (scenario 2), and the overall footprint for the entire event (combination of scenarios 1 and 2) separately.