Yes, there is the Swiss Pass. Available for 3, 4, 8 or 15 days. This is valid on all transport, trains, buses boats and city transport.
It is not valid (or only gives a reduction) on some mountain railways (for example Jungfrau).
Details here: https://www.sbb.ch/en/leisure-holidays/travel-in-switzerland/international-guests/swiss-travel-pass.html
For one day travel, there are various local offers.
There is also a "Berner Oberland Pass, valid for 3, 4, 6, 8 or 10 days. That covers the lower mountain lines, but still only gives a reduction on the final section of the Jungfrau.
Info: https://www.regionalpass-berneroberland.ch/en/
There are no multi-person offers like the German Länder tickets.