the motion-law of the Previous Segment is a Dwell or a Constant-Velocity.
you want the Position and Velocity of the Selected-Segment to flow from the END of the Previous-Segment.
In this case, the Position and Velocity at the End of Previous-Segment are specified at the START of the Previous-Segment
1.Click the Previous-Segment to make it the Selected-Segment
2.Edit the Position at the start of the Segment.
When the segment is a Dwell motion-law, the position at the Start of the Segment is also the position at the End of the Segment.
When it is a Constant-Velocity motion-law, the Position AND Velocity at the Start of the Previous Segment define by the Position and Velocity at the End of the Previous Segment.
Thus, when the Match Control-Button of the Next-Segment is active, the Start motion-values of the Next-Segment are also specified.