How to get historic position and department values on assigment report

Summary

My analysis brings in only current names of department and positions when I want the names that the were at the time of the segment

Content

When I run my attached analysis it brings in only current names of department and positions when I want the names that the were at the time of the assignment dates. For example - a position had a name change in March to Manager but prior it was lead. When I run my report the individual who has held that position previous to the March name change is showing as Manager as well (given the current name of the position is manager). The same issue is happening for Dept.