If you want to move nodes (to get a better overview), you have the following options:
Move the entire pipeline: Hold down the mouse button and drag a rectangle over the entire pipeline. Now you can move the selection by holding down the mouse button.
Move individual nodes in the pipeline: Either draw a rectangle over the desired node here too and/or select nodes individually with a mouse click. By clicking on one of the selected nodes and holding down the mouse button, you can move the entire selection.