Select the pipes at the end of a Multi-Pipe route, right-click, and select ( Place Multi-Pipe) from the context menu.

The Place Multi-Pipe dialog opens with the selected Multi-Pipe settings.

Click (Swap Order).

Using this option depends on which side of the route you want the Multi-Pipe origin to be which depends on the obstacle you are trying to circumvent.

The Place Multi-Pipe dialog closes. The Multi-Pipe is attached to the pointer allowing you to extend the route.