AWS Security Hub now allows you to designate an aggregation Region in AWS GovCloud (US) and link some or all regions to that aggregation region. This gives you a centralized view of all your security findings across your accounts and linked regions. After you link a region to the aggregation region, your findings are continuously synchronized between the regions. Any update to a finding in a linked region is replicated to the aggregation region, and any update to a finding in the aggregation region is replicated to the linked region where the finding originated.
Source:: Amazon AWS