From FreeCAD Documentation
- Use the Std BoxElementSelection command to box select faces instead of objects.
- This command cannot be used to select elements in a sketch. To 'box select' when the Sketcher Dialog is open:
- Make sure that no command is active.
- Do one of the following:
- Click in an empty area and drag a rectangle from left to right to select objects that lie completely inside the rectangle.
- Click in an empty area and drag a rectangle from right to left to also select objects that touch or cross the rectangle.