Explain the problem as you see it
You can't currently use the same keyboard shortcut for multiple actions to build toggles. For example, I want CMD+O to be BOTH: Show Completed Items AND Hide Completed Items (basically to function as a toggle).
Why is this a problem for you?
The keyboard shortcut is muscle memory from Workflowy. It means I heave to learn another keyboard shortcut.
Suggest a solution
Support toggles for keyboard shortcuts. In this example... If the items are currently shown, hide them. If they're hidden, show them.