Under Legend Entries ( Series) inside the Select Data Source window, you need to select the sales values for the year 2018 and year 2019. This window helps you modify the chart as it allows you to add the series (Y-Values) as well as Category labels (X-Axis) to configure the chart as per your need. Step 3: As soon as you click on the Select Data option, a new window “Select Data Source” will open up in Excel as shown below:
