You can find the filter menu on the top of each view (above the main graph). From here, you may filter your data in two ways (by date and by player).
The first is to click on the Date Range or the Calendar Icon to filter by date. The default view is for the past 30 days, including today. Opening up the Date menu, you can either click on a predefined value (today/yesterday), or you can pick date range which opens up two calendar boxes. The left box is the Start Date and the right box is the End Date.
Additionally, you may filter your data using the Player Filter dropdown. Open the drop down and select the player that you want to view the data for.