To add in another dashboard to an entity you will want to click on the gear icon above the "Dashboards" section as shown below:
From here you will see your current Dashboard displayed. Next, you will need to click the "+ Create a Dashboard" button in the top right corner as shown below.
After you click the "+ Create a Dashboard" button a window prompting you to enter the name of you new dashboard will appear like the one below:
Enter the desired name of your new dashboard, click "Create Dashboard", and you will be able to add any charts to create a new dashboard.