Dashboard: how to navigate the sidebar through a lot of items

I'm working on an analytical dashboard to help an owner of a restaurant chain to analyse performances of his restaurants. Restaurants could be filtered in groups, depending on places (ie "Show me all the restaurants in that city.").

I'm now thinking about a sidebar with a simple filter: a list of places with a checkbox to let user compare metrics about selected areas: therefore user can look at some graphs about transactions or revenues.

What if user want to analyse performances of just one restaurant? Can you suggest me an alternative to a dropdown list with a checkbox for each restaurant, as shown in the image?