Autodesk Civil 3D has 2 buttons (Expand and Collapse) in some of its dialog boxes such as "Parameters" tab in its Corridor Properties.
I would like to see similar buttons in some dialog windows in MicroStation such as the "Element Templates Manager", "Text Styles", "Dimension Styles", etc... basically where there is DGNLib Libraries in a tree structure.
As MaryB suggested, you can post this in Ideas Forum section:https://communities.bentley.com/products/microstation/i/