How do you access UDT members in the Report Viewer

I have a UDT as a custom property of the report viewer but can not figure out how to access its members. I have tired things like:
@Sensor@
@Sensor.Status@
@Sensor[Status]@
@Sensor[‘Status’]@
@Sensor:Status@

I get results like the attached image (basically text details about the UDT or )