Hi @Tomas_Pesko!
I am truly sorry the notification of your follow up question did not reach me and I have only now discovered you posted a reply!
Instead of using Aggregate(…) function to group all users, I would suggest selecting Assignee user group import which would create a dimension with Assignee groups. Using user group dimension will make the Drill through faster!
Please let me know if you have further questions regarding this!
Lauma / support@eazybi.com