I was thinking of something like a sequence of SQL select like statements that will express this. But Iam not sure how it can take care of the overrides by the rules that follow.

If you do this with DBD::AnyData temporary-in-memory tables, or with any DBD that supports views and/or temporary tables, you can create a temporary table and apply the rules successively to that table. If all rules are written in the form "DELETE from temp_table WHERE ..." then you can successively apply the rules e.g. #1 would remove anyone not in CountryA-D and rule #3 would remove people from that list who lived in CountryC and state xx.

If you want to go the non-SQL route, I think YAML is likely to be your best bet.