Amazon FSx for Windows File Server, a service that provides fully managed native Microsoft Windows file systems, now enables you to use a single AWS Managed Active Directory (AD) with file systems across Amazon Virtual Private Clouds (VPCs) or AWS accounts.

from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/06/amazon-fsx-for-windows-file-server-now-enables-you-to-use-a-single-aws-managed-ad-with-file-systems-across-vpcs-or-accounts/