How to get the users name from users group?

Hello All,

I have created role "database-users" and inserted some of users inside it. Could you tell me which query to use for listing out those users name? I went through pg_users, pg_group but no luck.

CREATE ROLE database-users
  NOSUPERUSER INHERIT NOCREATEDB NOCREATEROLE;

CREATE ROLE "dbuser1" LOGIN
  NOSUPERUSER INHERIT NOCREATEDB NOCREATEROLE;
GRANT database-users TO "dbuser1";

CREATE ROLE "dbuser2" LOGIN
  NOSUPERUSER INHERIT NOCREATEDB NOCREATEROLE;
GRANT database-users TO "dbuser2";

How to query database-users to list the dbuser1 and dbuser2?

Thanks in advance,
Jack