The Groups overview is one way of finding out who is in which group. But that is half of what's needed. It gives a table showing each group and the members of that group.
What we also need is the other half, a table that shows each person within the course and the groups they are members of. Eg.
|Student 1||no group|
|Student 2||Group 1, Group 2|
|Student 3||Group 2, Group 3|
Preferably sortable by student firstname/surname
And, if that can be exported as an XLS or CSV that would be even better