To select several blocks, hold down the shift key and hold the left mouse click to draw a selection frame. The selected blocks will change to have the same colored frame.
In the simplified view (zoomed out), these same blocks appear white.
Simply hold and click on one of the blocks to move the selected set of blocks.
Zoom button +
The zoom + button allows you to gradually zoom in on your graph.
Zoom button -
The zoom button - allows you to gradually zoom out in your graph. As you zoom out, you will see that your graph switches to simplified view mode to get a better overview of your graph. The blocks are then composed only of their titles and keep the same color.
Adjust view button
The Adjust View button allows you to refocus and zoom out as much as possible the view of your graph.