How to restrict a code combination only for a specific responsibility

We have a requirement to restrict a code combination for a specific responsibility. It can not be achieved through key flex field security rules because through that functionality we can only restrict a specific segment value. Combination cannot be restricted. Other possibility is cross validation rules, but it can also not be used because it restrict the code combination at ledger level whereas we need restriction only at a specific responsibility level. Same combination would need to be used for other responsibilities.

In case there is no such standard functionality available, then kindly recommend some personalization.