A Goal Metric allows us to track our Dynamics 365 CE data against specific targets. For example, we may want to track our actual revenue for the fiscal period. To create a goal, first, we need to define goal metrics, which define how we are going to measure our goal. In goal metrics, we define the type of metric as to whether it is an amount or a count, and we define which fields will be part of the goal metrics. Following is the screenshot of Goal Metric which is available out of the box to track number of product unit sold:
Under Rollup Fields section, we can define which field we are going to use for tracking, for example, ...