Webi - How to use group by function and to make data distinct in that column

Hi Everyone

I'm a begginer in BO and i'm experiencing problems when trying to create a webi report that shows different courses, how many males and females in a course, their race and how many people attended each course. My challenge comes in wen i try to group by distinct courses:

For Example

Course name     Gender     Race         Attendees 

BEXX11             Female     Coloured    2

BEXX11             Male         African      1

C3                    Male         Indian        2

F3                    Female      White       1

BEXX11            Female      Indian        3

C3                   Female      Indian        4

Course name     Gender     Race         Attendees

BEXX11             Female     Coloured    2

                        Male         African       1

                        Female      Indian        3

C3                    Male         Indian         2

                        Female     Indian         4

F3                    Female      White       1

Thanks in advance