Expression Assistance Required


I need help with finding the exact expression for my use case. I have two Columns - Next Follow Up Date and Last Call Date. I want that when a used selects a new date in the Next Follow Up Date the previous date get’s automatically filled in the Last Call Date. I tried the _THISROW_BEFORE expression but not able to work it out. Kindly assist.


When i use _THISROW_BEFORE i get an error

_THISROW works fine

If i use () for _THISROW_BEFORE then it doesn’t pick the value from the column i want

Hi, any one having any idea kindly update