This is a planned addon to the marketing automation release. No ETA on specifics yet.
You can always export your customers from the setup -> account tab - that has the total_spent by customer, which you can sort to find your biggest spenders
Here is the full marketing automation guide here: https://learn.commentsold.com/marketingautomation
And the related release train here: https://helpme.commentsold.com/en/articles/3313864-release-train-9-5-2019