Data Access based on Contacts and Accounts Custom attribute

Summary

How to provide access to Contact and Accounts based on Custom attribute on Contact and Accounts compared to custom attribute on Resource

Content

Hi,

For our requirement, we have added Custom Attribute called 'Region' in Resource object ,Contact and Account object. We want to give access to resources based on this custom field Value. Eg: If a Contact has Region ='A', Users with Region ='A' should be able to see this Contact Record. What is the best way to achieve this?

Regards,

Nirosha