How to find existing Filterset in database replay ?

When implementing oracle database replay in 11gR2 , I received the following error while creating a filter set

SQL> exec dbms_workload_replay.create_filter_set(replay_dir=>'HISDMP',filter_set=>'v1026fs1',default_action=>'INCLUDE')

BEGIN dbms_workload_replay.create_filter_set(replay_dir=>'HISDMP',filter_set=>'v1026fs1',default_action=>'INCLUDE'); END;

*

ERROR at line 1:

ORA-20223: a filter set named "v1026fs1" already exists

ORA-06512: at "SYS.DBMS_WORKLOAD_REPLAY", line 6141

ORA-06512: at line 1

I searched for a while  any views that records existing filter set , but I could not find anything.

Anyone knows these views?