The DBA_SQL_FIREWALL_ALLOWED_SQL data dictionary view shows the SQL that a user is allowed to use.

For example:

SELECT SQL_TEXT, ACCESSED_OBJECTS FROM DBA_SQL_FIREWALL_ALLOWED_SQL WHERE USERNAME = 'HR';
 
SQL_TEXT                            ACCESSED_OBJECTS  
----------------------------------- ------------------
SELECT COUNT(*) FROM HR.EMPLOYEES   "HR"."EMPLOYEES'