If you only want to return rows where one column has a certain relationship (greater than, less than, etc.) to another column, use the Filter step to compare these columns.
In this example, we want to return only rows where our Adwords sales are higher than our Print sales. Here's the chart we're working with:
We'll add a Filter Rows step in the pipeline (Add Step > Filter Rows) with the following settings:
As you can see, rows where Print sales were greater than Adwords sales are removed.