To keep your readers a bit longer on the blog we automatically implement for all our MPS Themes the Related Post Widget. The Widget allowing your readers to discover similar posts to the one they have just clicked on.
Navigate to Appearance > Customize > Madrid Theme Options > Article Layout
Check the box where it reads Show Related Post so it will be displayed on the theme. Next you can decide what the Widget title should read. Last you need to decide how the Related Post Widget should work, you can choose between Tags and Categories. If you should use Categories for your posts then check Categories. Don’t forget to click on publish!