MacBook Pro, Ventura 13.4.1

Whilst working through the resolution of a previous issue (https://github.com/geany/geany-osx/issues/42) one pre-release version of Geany was able to show the document list as a hierarchical tree rather than a flat list. The subsequent release build (Sulamar 1.38 2023-03-25 with GTK+ v3.24.36 and GLib v2.72.0)) excluded this feature. Is there a setting to switch on the hierarchical view, or is it new feature which needs to be requested?