Employee details at the time of the absence

I would like to report on the worker details at the time of the absence. If for example an employee changed department today, the absence from last year would show the department they were in last year.

I attempted to combine the subject areas Workforce Management - Absence Calendar Details Real time and Workforce Management - Worker Assignment Event Real Time, filtering for sickness absence, however the Event FTE field is showing blank.

Any advice?

Thanks in advance!