DVT SystemVerilog IDE User Guide
Rev. 19.1.42, 6 December 2019

40.3.1 Folding

Collapse All Levels Fold to statement level.
Show Active Preprocessing  
Show First Level Collapse all levels then expand one level.
Expand All Levels Unfold code.
Toggle Current Line Fold/unfold.
Define Custom Region Create a folding marker for the selected region.