There currently is one option to travel by night train from Goteborg (Sweden) to Duved (Sweden), taking approximately 13 hours: Namely the 3904 operated by Snälltåget.
Snälltåget offers night travel with various comfort levels on night trains between European cities.
Accommodation ranges from individual seats in coaches to shared compartments with up to six berths and private compartments for small groups. All beds include bedding and blankets.
In shared and private compartments, seats convert to berths at night. Each compartment features three berths on each side with ladders to reach the upper berths. Private compartments are ideal for groups seeking more privacy.
Animals are permitted in private compartments only. Bikes are not allowed, but collapsible bicycles can be transported as hand luggage or stored on luggage racks.