When using existing Data Studio templates, charts and controls can sometimes change. This happens because of differences in the information gathered from a site. If a control, such as the Page Section Tracker Name or Department Header Name, changes to something unexpected, follow the instructions below.
Instructions
Click the Control box so that it is selected:

In the Control column, on the Setup tab, select the Control Field:

Change the Control Field to the desired dimension:

This will then change the Control Field on the report itself:
