Arisa, check if you have Activity Map enabled in your implementation. If it works, it's likely that the click-throughs from the banner to the destination page can be identified by using Activity Map dimensions. Then you may want to use Fallout to visualize the traffic coming through the banner.
Then, in the left rail, click "Pages" to show all of your tracked pages. Find the one you want to report on inflows, and drag it to the centre dotted box in the Flow visualisation. AA will then build a flow report for you, showing inflows (and outflows) through that selected page.