How to achieve Open Closed Principle if in the future you need to add more attributes?

The problem at hand is to identify Owners based on some logic then return back an object with all of those Owners. So if client needs 3 Owner then return back an object with those 3 Owners. Example: Owner A, Owner B, Owner C. That object will then be used to add on to another object, Account, that will be send to the Database.

I was thinking of creating an OwnerIdentifier interface that classes can implement. Then have a class that has a method that takes in a variable arguments that will iterate through all the OwnerIdentifier concrete implementation and the method returns back a Map<Owner, String>. Owner is an Enum type and String is the owner alias. Once I have the map I can use that to build the model.

HOWEVER, I'm not sure if that is really the best approach...... Because I would have to then map the values in the Map to a particular field in the Account object. Then if new type of Owner are added, I would have to change the Account object...

Any suggestions would help a lot!!!