Mine

[sub-access_control]
; ARG1 -- user_id
;
exten => s,1,NoOp(sub-access_control start)
exten => s,n,Set(USER_ID=${ARG1})
exten => s,n,GotoIf($[${ISNULL(${USER_ID})}]?error,1)
exten => s,n,Set(HASH(access_control)=${ACCESS_CONTROL_DATA(${USER_ID})})
exten => s,n,Set(X=1)
exten => s,n,While($[${EXISTS(${CUT(HASHKEYS(access_control),\,,${X})})}])
exten => s,n,Verbose(1|Value of HASHKEY ${CUT(HASHKEYS(access_control),\,,${X})} is --> ${HASH(access_control|${CUT(HASHKEYS(access_control),\,,${X})})})
exten => s,n,Set(X=$[${X} + 1])
exten => s,n,EndWhile()