You can now use the shortcut "c" to collapse/uncollapse all groupings to reveal/hide all underlying features.
On the Features board
This shortcut works for the By Hierarchy, By Release, and By Status groupings. Also, when on Sorted list, features will expand/collapse to show/hide underlying subfeatures.
On the Roadmap
This shortcut works for the By Hierarchy and By Objective groupings. Also, when features are viewed as a flat list, features will expand/collapse to show/hide underlying subfeatures.
In productboard, press ? at any time to view all keyboard shortcuts.
Available on all plans