It is not yet possible to get the address of the central device via the scan request at an application level. Can you let us know any specific reason for you to get the address in the scan request packet.
Also, after establishing connection, the device address of both the central and peripheral device can be known.
Ah that's too bad. I would like to be able to passively track nearby devices that aren't advertising. Devices that do not advertise can be detected by offering scan response data.