For now i use CALLERID(name) to identify whos park a call, but, i think, it is not a good solution

[fop2-park]
exten => _X.,1,Set(ARRAY(RETURN_EXTENSION,RETURN_CONTEXT,PARKBUTTON)=${CUT(EXTEN,:,1)},${CUT(EXTEN,:,2)},${CUT(EXTEN,:,3)})
exten => _X.,2,GotoIf($["${PARKBUTTON}" = "PARK/default"]?5)
exten => _X.,3,GotoIf($["${PARKBUTTON}" = ""]?5)
exten => _X.,4,Set(PARKINGLOT=${PARKBUTTON:5})
exten => _X.,5,Set(CALLERID(name)=______________${RETURN_EXTENSION})
exten => _X.,6,Park(,${RETURN_CONTEXT},${RETURN_EXTENSION},1,s)