Get a recording of Aretha's :The House that Jack Built" And break it down, until you can play exact with the drum kit. Duck is about 2 and 4, and is all the old soul and R&B material, Chuck Rainey, Willy Weeks, etc.. Check out Jamerson doing this stuff- amazing how he could change the feel of the tune with simple note placement- laid back here, on time there, ahead right before the bridge, etc.
A laid back feeling is the 4, not the 1. But the whole laid back R&B thing is not built on the one it is built on 2 and 4. Funk is more about the 1. Go find you some old soul or motown drum loops and work with them.
Do this- walk in or march in place, in tempo, with a metronome playing- left foot on 1 & 3, right on 2 & 4. When you got that tight, then do this: Clap on all the beats, exactly with your feet. Can't do it, huh? Few can. But work at it, until you have you hands, feet and the metronome all tight & together. Next, clap on just 2 & 4. Make that nice & tight, too, until you can do it at different tempos and keep it together with and without the metronome.
Now you are halfway there: the next part is to sing your bass part while clapping your hands or marching- it's not the pitch that counts, it is the rhythm. Do this until you can feel where the bass notes fall in time.
Now go do the thing carol Kaye talks about- play, while tapping your foot on 2 & 4. that is where the groove is. By the time you have this down, you will know how to lay back and push.
Groove comes from your body, not your head- learn to feel the groove of the song before you play a single note.