EasySocial : How 'Member A' know all events subscribed by 'Member B'?

Hello

Here is the story:
- Member1 goes to Group A and subscribes to an 'Group Event' A related to Group A
- same Member1 goes to Group B and subscribes to an 'Group Event' B related to Group B
- same Member subscribes to a general Event C
=> as Member2, I would like to know ALL the events where Member1 subscribed, ie, A, B and C


==

applied on our specific context:
- one Group = one marathon (ex. London)
- our members discuss this marathon in this group
- there is a group event with the date of the marathon, the members who will run this marathon register to this event
=> another Member would like to know the list of marathons (=list of group event) of a specific Member1

Thanks
Henri