You can toggle between displaying or hiding your Forecast Items within any tab in the Forecast on an individual basis. You can do this by pressing the triangle which appears adjacent to the account line. This allows you to expose the Forecast Items on lines you wish to see further detail and keep items hidden on those you don't.
In this example, we're going to expose the Forecast Items on our Sales line. To do so, we first need to navigate to where our Sales line appears on our Chart of Accounts:
Adjacent to our Sales line we'll find a triangle. The triangle will only appear when a Forecast Item has been created on the line:
The triangle serves as the 'show/hide' toggle, allowing us to decide whether we wish to display or hide Forecast Items. To show our Forecast Items for this line, we simply need to press the triangle. This will cause items to be displayed below Sales, but not expose items for any other line:
To hide the Forecast Items on our Sales line we can simply repeat the same process - press the triangle again and the items will disappear: