Group by columns from two tables

Folks, new to PBI Desktop.
I am extracting user and group memberhsip data from Active Ditectory in PBI Desktop.
I have two tables (user, group) that are joined with a relationship (1 to many).

The table looks like this:

I want to display the data in a tabular format as follows:

It's basically group by username and usernumber.
How do I do that in DAX (or any other method)?
Thank you.