How to use JSL for Fit Group with by column?

[#1]

Not sure what is erroring out in this script using Fit Group in JSL. It still plots the graph as I wanted, however it terminated the script at that point.

In the following script, error marked by /*###*/
Fit Group(
	Bivariate(Y(:A), X(:AAA),
	Bivariate(Y(:A), X(:BBB)),
	Bivariate(Y(:A), X(:CCC)),
	Bivariate(Y(:B), X(:AAA)),
	Bivariate(Y(:B), X(:BBB)),
	Bivariate(Y(:B), X(:CCC)),
	<<{Arrange in Rows(3)},
	By(:Group123) /*###*/
);

[#2 · Accepted solution]

I assume the issue is that the By needs to be associated with each of the separate Bivariate instances

Fit Group(
	Bivariate(Y(:A), X(:AAA),By(:Group123)),
	Bivariate(Y(:A), X(:BBB),By(:Group123)),
	Bivariate(Y(:A), X(:CCC),By(:Group123)),
	Bivariate(Y(:B), X(:AAA),By(:Group123)),
	Bivariate(Y(:B), X(:BBB),By(:Group123)),
	Bivariate(Y(:B), X(:CCC),By(:Group123)),
	<<{Arrange in Rows(3)}
);

[#3]

Thanks!