I'll take a shot at it.
First, make certain you know your Gb major scale and how to finger it on your bass. This song is structured very wide open, so it leaves a lot of room for the bass player to do different things. As long as you emphasize the Gb and the B, and land there when the keyboard lands there, you'll find a lot of room to craft your own lines and make the song sound alive
Gb Major Scale
Gb is E string 2nd fret
Ab is E-String 4th fret
Bb is A-string 1st fret
B is A-string 2nd fret
Db is A-string 4th fret
Eb is D-string 1st fret
F is D-string 3rd fret
Gb is D-string 4th fret
Most of the feel of the song comes from bouncing back and forth between the IV (B) and the I (Gb). Occasionally toss in the A-flat as a passing note. Occasionally walk up to the higher Gb on the D-string. When I play along to the song you linked to, I find that skipping the F in the scale progression sounds best and fits in better with what the keyboard was playing.
