Your peers are determined by your company's industry, and thus mainly by the product type you have in your company settings, e.g. clothing & fashion or food & drinks.

You can check and change your benchmarking settings here: https://www.compass.co/settings/benchmarking. 
With a growing database we will be adding product types and refining the existing ones.

The goal of benchmarking is to know where you are at compared to where you could be. You benchmark yourself against your peers because you want to know where to focus on, what metrics to improve.

Depending on the metric, we sometimes use other company specific information to determine your peers. For example, our analysis has shown that for Conversion Rates it isn't so much the industry that determines how high your conversion rate is or can be, but rather the price of the product. If you have a relatively expensive product, Conversion Rates are bound to be lower than other store's conversion rates. Therefore, for this metric, your peers will be stores with a similar average transaction value to your's rather than the stores in your segment.

We want you to know what a good value is for your store, so that you can set yourself a goal.