Here is a script that runs against a sample data table that creates an ID column with a formula as you want
Names Default To Here( 1 );
dt = Open( "$SAMPLE_DATA\cars.jmp" );
dt << New Column( "ID",
	formula(
		If( Row() == 1,
			Summarize( drugs = by( :Make ) )
		);
		Contains( drugs, :Make );
	)
);
					
				
			
			
				
	Jim