To compare segments, click on the name of the segment, then on Results.
Choose another segment and click Add to Comparison. You may add multiple segments.
When you've added all the desired segments, click on the Run Comparison button on the lower right side of the page.
Give the system a moment (maybe more than one if you've added multiple segments). You'll see this briefly.
You will soon see your results. Note the Save as Crosstab button, which allows you to save your results.