I remember that this option is possible by dragging multiple columns onto the axes.
With the new option ,they will automatically be used in pairs:

To use this mode (instead of Interval) you can calculate the "3" points as transform columns:
Graph Builder(
Transform Column( "py+vy+ay", Formula( :py + :vy + :ay ) ),
Transform Column( "py+vy", Formula( :py + :vy ) ),
Transform Column( "px+vx+ax", Formula( :px + :vx + :ax ) ),
Transform Column( "px+vx", Formula( :px + :vx ) ),
Size( 483, 459 ),
Summary Statistic( "Median" ),
Variables(
X( :px ),
X( :"px+vx"n, Position( 1 ) ),
X( :"px+vx+ax"n, Position( 1 ) ),
Y( :py ),
Y( :"py+vy"n, Position( 1 ) ),
Y( :"py+vy+ay"n, Position( 1 ) )
),
Elements(
Line(
X( 1 ),
X( 2 ),
X( 3 ),
Y( 1 ),
Y( 2 ),
Y( 3 ),
Legend( 5 ),
Ordering( "Within Row" ),
Connection( "Arrow" ),
Summary Statistic( "Mean" )
)
)
);

don't know how to distinguish between the 3 segments if all 3 are parallel ...