Custom sidebar entry with only one subgroup

I copied the code without any changes from the tutorial.

    {
    categories = (
        {
            name = "Compatibility";
            icon = compatibilityTemplate;
            subGroup = (
                {
                    name = "Web";
                    coverage = (
                        .notdef,
                        hyphen,
                        space
                    );
                }
            );
            subGroup = (
                {
                    name = "Windows";
                    coverage = (
                        nbspace,
                        softhyphen
                    );
                }
            );
        },
    );
    languages = (
        {
            name = "Esperanto";
            icon = EsperantoTemplate;
            script = esperanto;
            subGroup = (
                {
                    name = "Letters";
                    coverage = (
                        Ccircumflex,
                        ccircumflex,
                        Gcircumflex,
                        gcircumflex,
                        Hcircumflex,
                        hcircumflex,
                        Jcircumflex,
                        jcircumflex,
                        Scircumflex,
                        scircumflex,
                        Ubreve,
                        ubreve
                    );
                }
            );
            subGroup = (
                {
                    name = "Marks";
                    coverage = (
                        circumflexcomb,
                        brevecomb
                    );
                }
            );
        },
    );
}