Only allow to enroll into Spouse Supplemental Life, If Employee is enrolled in Supplemental Life

We have 3 plan types (Employee Supplemental Life, Spouse Supplemental Life, Child Supplemental Life)

Requirement is Employee should only be able to enroll into Spouse or Child, if they he/she has opted into Employee Supplemental Life.

We are achieving this by Post election edit role and it fails sometimes.

Do we have any other way to restrict this?

Thanks

S