The Category Performance Comparison lane acts a bit differently than the other lanes, and so has different sorts of parameters to set in order to see what you’d like to see. You’ll have two options. 
You can choose:
Category for Comparison: This option allows you to select a “lens” of sorts through which you can view your inventory/stock. Whether a publisher-generated set of classifications like BIC (UK) or BISAC, or using your own POS system’s categories, you can view your entire stock , split out accordingly, and then compared and ‘rated’ according to performance.
Time Frame: You can see activity for a few months, or for a year, depending on what you’re doing. Generally, you’ll probably look at a timeframe of a year. There may very well be times when you want to see how your shops’ different categories performed after, say, the holiday or summer seasons.
