You can use the Select tool to set components to the Selection Basket and to remove them from it.
To set a component to the Selection Basket:
Select the Select tool from the main toolbar.
Click a component in the 3D view. The component turns blue to indicate it's now part of the current Selection Basket:
To add more components or to select multiple components at the same time, press Ctrl (Windows) or Cmd (macOS) and click the component.
To remove components from the Selection Basket, press Ctrl/Cmd and click.
If the component is part of the selection, it will be removed and turn from blue back to its default colour.
If the component you have clicked on is not part of the selection, it will be added and turns blue.
To use the Select tool with multiple components, use the area selection method:
Place the mouse in a free area of the model. Click and hold the left mouse button (do not move the mouse) for approximately one second.
A new icon appears. You can now drag and define an area to be selected:
Window: Move the mouse from left to right to invoke the 'window' selection method, where all components must be fully inside the rectangle to be selected.
Crossing: Move the mouse from right to left to invoke the 'crossing' selection method, where all components can be inside or touching the rectangle to be selected.
If you use Ctrl + click (Windows) or Cmd + click (macOS) during this process, you can add or remove components from the current Selection Basket content.
Release the left mouse button.