If you're looking to calculate a score based on other score values you can create your own formulas to produce a new score.
For example, if you're looking to output the total volume of an athlete moved based on 2 other workout scores (Workout A and Workout B)
Create a workout
Set the Scoring Type = "Calculated"
Set a label of your calculated score, for example, Total Volume
Click on Expression Builder, from there, click on the workout you'd like to formulate and apply an arithmetic operator.
In the example below, we are taking the "Repeat" workout and multiplying to with the "Games Style" workout.