Copy to another field value next.breach

Hello Community.


In interaction table(in my system "incidents") a have field next.breach.
After close interaction SD, status="closed", value in field next.breach=NULL.
I need current value in this field, but i can't find where created and changed value in this field.
I created new field DATE/TIME hpc.exp.dt, and in format control(table incidents) added new calculation
hpc.exp.dt in $file= next.breach in $file(Add=true,Update=true). But when i create new interaction in new field hpc.exp.dt no change.

Tell me please how to fix it? My system HP Service Manager 9.31.