Reverse entity reference filter

Problem/Motivation

How can we filter node types when adding a Computed field (Reverse entity reference)?
For example, the field_person is available for all three node types. What if we only need to compute fields of type School?

Note types: Class, School, Organization,

Ex: "node.field_person on School entities" instead of "node.field_person on Content entities"

Any idea, please.. Thanks