This feature is located in the Charts menu.
Use this button to display on the selected chart the compound annual growth rate between the first and last points of the chart (see picture below for an example on a waterfall chart).
The CAGR is computed as
Using the number of points in the series as number of years, and by computing end and initial values by summing across the series (see below for a simple example with 2 series).
1) For stacked and standard Waterfalls, the number of years is automatically adjusted to the number of 'pillars'.
2) When you update the chart source data, the CAGR is not automatically updated. To do so, you can either reinsert the CAGR on the chart, or click the Update Charts button. If no chart is selected, this button will also update all the CAGR boxes found in the workbook.