AWSTemplateFormatVersion: 2010-09-09
Parameters:
  QSS3BucketName:
    Default: aws-quickstart
    Type: String
  QSS3KeyPrefix:
    Default: nested-create/
    Type: String
Conditions:
    GovCloudCondition: !Equals
      - !Ref AWS::Region
      - us-gov-west-1
Resources:
  ChildStack:
    Type: AWS::CloudFormation::Stack
    Properties:
      TemplateURL: !Sub
       - 'https://${QSS3BucketName}.${S3Region}.amazonaws.com/${QSS3KeyPrefix}templates/test.template_nested.yaml'
       - S3Region: !If [ GovCloudCondition, s3-us-gov-west-1, !Sub 's3.${AWS::Region}' ]