Call recording for forwarding call to external number

I am stuck with a problem. scenario is
party A (outside caller) calls to Party B on a number configured direct line, B call forwarding on mobile is configured. if B picks up call on telephone set, it record but if the B call forwarded on mobile it isn’t recording.
Call recording is set for inbound-outbound always.
But, when A & B forwarding comes, the call is between A and Asterisk Channel. Is there anyway i can record/monitor on channel level. as this way i can record all calls on channel level