The "Update/Overwrite" feature can be used to update or overwrite column values within matching groups.



For example, on the following duplicate group we notice that the allocated Master Record does not have any data for "Contact Name" and "State", as shown below:



To populate these values, we can use this option to populate those missing with the most popular value.


As shown below, we specify "Most popular value" for both the "Contact Name" & "State"

Keeping the Update only Empty Values  ticked will ensure that only entries with empty values will be updated. 



Clicking the "Update" button will produce the following results; notice the "Contact Name" & "State" columns on the Master Records are now populated with the most popular value: