If you watch really closely in Dune P1, you can see another planet (presumably Selusa Secundus) through the center of the navigator ship. I don't know how it functions mechanically in his version, if they're navigating wormholes somehow or controlling them, but they have some form of wormhole mechanism shown in the series.

Edit: The image embed didn't seem to work, so here's the link to the image. https://www.reddit.com/r/dune/s/pSBHvR3Ser