FYI.
Since Bro upbeat have PM me privately on this question. I think it's good to share more in the forum on Rao2 direction. If travel from JW Marriot to Ratchayothin via BTS. How to go there?
JW Marriott is near to Nana BTS. Nana BTS to Mo Chit BTS is about a distance away. Mo Chit BTS to IMax Cinema is much nearer.
When reached Mo chit BTS, You can take free BTS shuttle bus from Mo Chit BTS. Take Bus No 1. Mo Chit - Central Lad Prao - SCB Park Plaza. The loop takes in the Mo Chit Station and Central Plaza/Central Department Store, and Sofitel Hotel and back via SCB Plaza. Saves 40 Baht in a taxi from the station. [SCB = Siam Commercial Bank Plaza]. Also within walking distance to the IMax 3D Cinema.
Map of Free Shuttle Bus Route
Hope this help.
chok dee krup.