Combo Overlay with average overlays

This page describes a use case for implementing a combo overlay.

Use Case Description

In an area, the locations for a clinic, a school and a sports center are known. Which area is for all three locations within a one kilometer range?

For this we would need to combine three AVG grid overlays, one for each location. then we would need to combine these three ranges in a new combo overlay, linking all three AVG overlays with a formula.