Hello Thoawhejaur87
The travel direction should also be indicated on their seat map although MOB has the most customer unfriendly website of all Swiss railway companies.
Best to talk with the Golden Pass customer service team as this train is operated by MOB and not by SBB. They might be able to reserve a seat right in their reservation system.
Tel. +41 21 989 81 90 (from US 011 41 21 …)
Email info@mob.ch
Every day: 9:00 – 12:00 / 1:30 – 4:30
Kind regards,
Roland