If I'm understanding you correctly you mean you want to move the first bass note? The easiest way to do that is.............
 
1. Zoom in on the track so you can easily see the wave form of the note you want to move. 
2. Split the clip at the end of the note so you have one small clip with the single note in it. (hold the alt key down and left click at the point you want to split - you may need to adjust snap settings for resolution and snap to zero audio crossing point)
3. Nudge or click drag the note to the required position.
 
If it's a more complicated bass line then Audiosnap may be needed but for just one note the above should suffice.
 
Fire away with any more questions if you need