In principle, every tenant with Swiss nationality is of course entitled to rent a rental vehicle from another EU country and use it for their holiday. It is only important that the vehicle is registered at a border customs office when entering Switzerland for the first time. More information can be found here.
The customs office issues every Swiss citizen a "Vormerkschein", which allows the use of a vehicle (that is not registered in Switzerland) and is valid for 8 days. If the vehicle is first used abroad, these days will be deducted. Within this period, the vehicle may only be used in Switzerland for three days and must then be exported again.
More information and road trip ideas can be found here: Rent a camper van in Switzerland