To select lidar based on classification, right-click on the layer in the Control Center, and choose Select Lidar Points by Classification... from the Layer sub-menu, or press the Select Lidar Classes button in the Lidar Toolbar.
This tool requires Global Mapper Pro.
This tool will bring up a dialog Select Lidar Classesshowing the available classes in the layer.
Check the box next to the lidar classes to select. Only classes in the current point cloud will be displayed in the dialog.
Add Points with Selected Class to Existing Selection?
Enable this option to add the points to any current digitizer selection. When unchecked, the lidar class selection will replace the current digitizer selection.