How to group by one field in table

I can’t seem to figure out how to group my table the way I want. In the below example, I want this table to look like it does in the screenshot, but have the Department column grouped so the user can expand/collapse departments.

If I try to switch to a pivot table, I get this but I don’t want all these expand/collapse options on my detail rows. I only want the department column grouped.

Personally I am unaware of a way to expand/collapse only one column. So if anybody knows of a way please correct me. My recommendation for a workaround would to be add a multiselect list control to the left of your visual and filter on that…