Use "Add Column via Lookup" to bring insights from a grouped table into a flat table

Let’s say you have a flat table of customer orders like below and you want to know whether a particular customer has placed multiple orders.

To find that out, you can duplicate the table and then group by the [Customer Name] column. Perform a row count calculation of the group. If that result is greater than 1, then that particular customer has ordered multiple times.

But what if you needed that [Repeat Customer?] insight to be present inside the original flat table? No problemo! Use the Add Column via Lookup feature to pull those values back into the original table: