Multiple Grouping in a Report

[CrisBene]

Good morning,

I'm trying to make a list report about users, groups, and roles.

In particular, I would like to group records by users' groups and then group by users again to obtain a single record per user with a list of roles instead multiple records per user. This is the actual table I tried to build in my report:

Group	User	Role
Group 1	User 1	Role A
Group 1	User 1	Role B
Group 1	User 2	Role A
Group 1	User 2	Role C
...	...	...

This is the situation I would like to have in my report instead:

Group	User	Role
Group 1	User 1	Role A, Role B
Group 1	User 2	Role A, Role C
...	...	...

I first created a database view with sys_user_grmember and sys_user_has_role tables.

Could someone help me? Thanks!

Have a nice day,

Cristopher