How to identify change in a column?

What node can I use to identify a change in a column?

I have a table with a column that details a lot number. I need to highlight in the table when that number changes, so I can then look up data in another column for the date and time stamps when it changed.

I’ve tried Group By and created a new column to identify the chosen row (when the number changed) and everything is listed as a duplicate. Is there a better function to do this where I can highlight the row and the subsequent 5-6 rows after the change?

Any help would be appreciated, I’m just starting out using Knime.