https://www.telerik.com/products/winforms/documentation/knowledge-base/cascading-comboboxes-in-property-grid
WinForms Cascading ComboBoxes in PropertyGrid - Telerik UI for WinForms
Learn how to achieve cascading combos in the WinForms PropertyGrid.
winformscascadingcomboboxespropertygridtelerik
https://mail.gnome.org/archives/glade-devel-list/2008-April/msg00008.html
[Glade-devel] Glade freezes trying to populate comboboxes
gladedevelfreezestryingpopulate