From the toolbar click the Box Selection icon . Shortcut Control + B (Windows) and Command + B (Mac) will also enable the Box Selection feature.
The cursor will change to indicating your in box selection mode.
Holding your left mouse button down and dragging the cursor from Left to Right will select parts completely within the box.
Holding your left mouse button down dragging the cursor from Right to Left will select parts completely within the box and any of those parts intersecting with the box. NOTE: If you wish to include additional data to your selection, you can do so by holding down the Control key and continue to select data.