1. In Formatting Property click on Series Property.

2. Enter Following details in Series General Property:

Select Series Type: Radar Area
Series name: Add appropriate name as required
Opacity: Controls the visibility as per required.
Hide series: By enabling this user can hide the series.

3. Fill above details in edit box, As Shown in figure:

4. Click on Preview and Save and Exit.

5. Now, match your Radar chart with the below example, it should look like the figure below: