you should first ask if there's a data source for CSA service desk that linked with the user table.
another solution to create a view in DB to have the columns you want then pull them into xtraction
You do not need both views. Based on your description of what you are trying to report on, everything should already exist in that combined ticket view.
That combined ticket view already has 4 mappings to the Contact table, representing each ticket's Group, Assignee, Created By, and Customer. It sounds like you are interested in the Group mapping that already exists.
Below is a screenshot taken while setting up a dashboard showing what you need (and a little more).
(1) Set the appropriate filters. To report on all open tickets, you want the filters for "Active Equals Yes" and "Status Does Not Equal Resolved" (you may need to repeat this one if you have multiple "resolved" statuses.
(2) From the Group Component section, under the display type you desire (pie chart, bar chart, grid, etc.) drag "Group" over to get the Top 10 Groups with open tickets (of all types, because you are using the combined ticket view)
(3) From the Group Component section, under the display type you desire (pie chart, bar chart, grid, etc.) drag "Assignee" over to get the Top 10 Analysts with open tickets (of all types, because you are using the combined ticket view)
Not shown: You could drag over a Group Pivot (use the grid view) for "Group" and then "Ticket Type" to get the same Top 10 Groups with open tickets, only further broken down by ticket type.
I hope this helps. Let me know if you have any questions about anything above.