The cable routing device most commonly used is called a "FLEXGUARD" and is available here:
https://www.etrailer.com/RV-Slide-Ou...LC1346271.html
Essentially, it's a piece of flexible plastic that folds as the slide retracts and unfolds as the slide extends.
You can make a temporary one from a strip cut from an old plastic rolling chair pad or even a sheet of rubber gasket material. I've "made a temporary repair from a 5 gallon bucket lid. Use your imagination, but there are photos of the flexguard both as parts and installed under a slide at the link above.