If you interactively run graph builder, all you have to do to have multiple columns plotted as the Y axis, is to grab all of the columns you want to graph, and to drag them to the Y drop zone.

The JSL to do this is below
names default to here(1);
dt=open("$SAMPLE_DATA/semiconductor capability.jmp");
Graph Builder(
	Size( 534, 456 ),
	Show Control Panel( 0 ),
	Variables(
		X( :NPN1 ),
		Y( :PNP1 ),
		Y( :PNP2, Position( 1 ) ),
		Y( :NPN2, Position( 1 ) ),
		Y( :PNP3, Position( 1 ) ),
		Y( :IVP1, Position( 1 ) ),
		Y( :PNP4, Position( 1 ) ),
		Y( :NPN3, Position( 1 ) ),
		Y( :IVP2, Position( 1 ) )
	),
	Elements(
		Points(
			X,
			Y( 1 ),
			Y( 2 ),
			Y( 3 ),
			Y( 4 ),
			Y( 5 ),
			Y( 6 ),
			Y( 7 ),
			Y( 8 ),
			Legend( 5 )
		),
		Smoother(
			X,
			Y( 1 ),
			Y( 2 ),
			Y( 3 ),
			Y( 4 ),
			Y( 5 ),
			Y( 6 ),
			Y( 7 ),
			Y( 8 ),
			Legend( 6 )
		)
	)
);
					
				
			
			
				
	Jim