show grants for {role} includes grants for roles it is a member of

MariaDB [(none)]> CREATE ROLE role_1;

Query OK, 0 rows affected (0.01 sec)

MariaDB [(none)]> CREATE ROLE role_2 WITH ADMIN role_1;

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> show grants for role_1;

+--------------------------------------------+

| Grants for role_1                          |

+--------------------------------------------+

| GRANT role_2 TO 'role_1' WITH ADMIN OPTION |

| GRANT USAGE ON *.* TO 'role_1'             |

| GRANT USAGE ON *.* TO 'role_2'             |

+--------------------------------------------+

MariaDB [(none)]> show grants for role_2;

+--------------------------------+

| Grants for role_2              |

+--------------------------------+

| GRANT USAGE ON *.* TO 'role_2' |

+--------------------------------+