Whether you're adding a new chart to a board, or a new metric to a block, you can access your class and location data from QuickBooks the same as any other data.
From the data navigation menu:
Select Data Source > QuickBooks > Profit and Loss by Class
Then, drill into the metric you'd like to add by class. After drilling all the way down, you should see the respective class.
For location data, go to: Data Source > QuickBooks > Profit and Loss by Department and follow the directions above.