Select hidden or hard to reach objects in FreeCAD.
The repository must be cloned into the Mod folder of FreeCAD (usually ~/.FreeCAD/Mod). Use the following command to install the add-on:
git clone https://github.com/drhooves/SelectionTools.git \
$HOME/.FreeCAD/Mod/SelectionTools
Press S,E while hovering above a object in the 3D view to invoke the selection process. Choose the sub object from the context menu that you want to select. The context menu shows only the sub objects intersecting a imaginary ray from the camera through the cursor. The shortcut can be customized in preferences window under Preferences->Display->Selection Tools.