To fold or unfold a code fragment,
press Ctrl+NumPad - / Ctrl+NumPad + .
GoLand folds or unfolds the current code fragment, for example, a single method.
To collapse or expand all code fragments,
press Ctrl+Shift+NumPad - / Ctrl+Shift+NumPad +
To collapse or expand code recursively,
press Ctrl+Alt+NumPad -/Ctrl+Alt+NumPad +.
GoLand collapses or expands the current fragment and all its subordinate regions within that fragment.