POET with Cross Validation Rules

I have a customer who has Departments used across Companies, they are a Financials only implementation. They enforce cost center / company combinations through cross validation rules as in some cases the departments are unique to the Company.

We are now implementing PPM for them and need to 'mirror' the cross-validation rules with the allowable combinations of Company / cost centers. Setting up unique company/cost center departments is not an option.

I've traversed the documentation and haven't really found a way to meet this requirement.

Thank you.