Currently in the app, you are unable to view past session. However, there is still a way that you can view your past sessions outside of the app!
If you log into the WebApp (app.diamondkinetics.com), with the same account that you are logged into within the Diamond Kinetics app, you will be able to view your past sessions, by selecting the "Sessions" tab.
To view all of your profile's history in the WebApp, click on the avatar in the top right corner of the WebApp. After you select that, there will be a drop down of the names of the profiles along with the avatar of each profile for you to choose which history you would like to see!