Technically, you do not create FACILITY's. You take an existing FACILITY and rename it for your use.
FACILITY's in CA Top Secret are predefined when you format the CA Top Secret security file SECFILE. USER11 through USER255 are the predefined FACILITY's.
You rename them to something meaningful for the type of application or address space you are using them with.
USER22 is renamed to FTP.
USER01-USER11 are already taken and used for default FACILITY's CICSPROD, CICSTEST, BATCH, STC, IMSTEST, IMSPROD, etc.