CREATE ROLE rolename [WITH EXTERNAL ('CN=Active_directory_group,CN=Users,DC=home,DC=network')];
rolename - The name for the new role. Optionally, enclose in single quotes. rolename is a case-sensitive VARCHAR(128).
WITH EXTERNAL - keywords that associate rolename to an pre-existing Active Directory group. CN and DC values are specific to your Active Directory installation.
CREATE ROLE 'myRole1';
CREATE ROLE 'engineering' WITH EXTERNAL 'CN=Engineering,CN=Users,DC=engineering,DC=myCompany,DC=com;