How do i create a simple log with previous column value ?

Hi,

I have an app currently running, and i want to make a simple change but i cant seem to find out how.

I have a column where the user can change its value with “+” and “-” buttons, and i want to display at the bottom of the table (in app ) the previous value of the column that was changed. I allready tried using the [_THISROW_BEFORE] but it only displays the current value.

Hope i was clear enough. Thank you in advance !