When you select the time in the past, it changes the screen as you see. Next, you can click on the instance inside the server. If you do that, at the top of the screen, well, below the tool bar and the timeline, you should see the instance name and a list of databases. You can scroll down on that screen to see the list of top queries for the time in question. You can look at duration or resources used. To exactly nail it down, you may need to move the time to just after the queries completed. It usually takes a little investigation. Moving the time just requires you to bump it forward or back using the buttons at the top of the screen.