So, changing the bounds of the slider is available in both the Activity Builder on teacher.desmos.com and on the Desmos calculator. You can’t hide folders directly in Desmos calculator.
However, you can do all of your work in the Activity Builder graph, hide the folders, then scroll all the way to the bottom and click “edit graph on Desmos” then, in the graph that opens in Desmos calculator, hidden folders will not be visible.