Suggestion on trains that split during the journey

I read, some of the trains one half of the train goes one direction and another half another direction. I would like to know which trains are those and I should be mindful of that. I would be travelling train from Zurich to Interlaken, from interlaken to Lucerne and then to Zurich. Also planning on taking Glacier Express as well. Then ofcourse the trains to the mountains. I would like to know list of trains which fall into this category where part of the train goes one direction and another part to another direction. I would appreciate any information on this...Thanks

Trains that split on route seem to be relatively rare in Switzerland, compared to some other European networks: very few of the longer-distance domestic services do this. However, one example you are likely to come across is the narrow gauge line into the mountains from Interlaken (the Berner Oberland Bahn), where trains leave Interlaken Ost with sections for Lauterbrunnen and Grindelwald, dividing at the second stop (Zweilütschinen), with the front section going to Lauterbrunnen and the rear section to Grindelwald. In summer, at least, each section is normally 6 or 7 coaches in length - they are always well-marked as to which section is going where, and staff on the platform can help.

I've a feeling that the Glacier Express is sometimes divided at Brig (going east) and Disentis (going west) because only shorter trains can be hauled over the Oberalp and Furka passes, but all coaches still go to the same place and are re-attached at the end of the mountainous section. I don't know if this still happens, however.

Thank you so much jwkibble for the information.