Switzerland

There isn't a direct one. You can go Geneva to Bern, Bern to Interlaken, then Interlaken to Lauterbrunnen. It's not as bad as it sounds, though; having done that trip myself, usually you get off one train and then next one you need is just across the platform. The Interlaken station and Lauterbrunnen stations are not large, either. Bern is big-ish but not like Gare du Nord or Euston big.

Plan your trip on the SBB website: https://www.sbb.ch/en/buying/pages/fahrplan/fahrplan.xhtml

Geneva to Bern. Bern to Interlaken. Interlaken to Lauterbrunnen.

Thank you ,