How to format the group header for different levels of grouping in Xamarin.Forms ListView(SfListView)?

<syncfusion:SfListView.GroupHeaderTemplate>
    <DataTemplate>
        <ViewCell>
            <ViewCell.View>
                <StackLayout BackgroundColor="{Binding Level, Converter={StaticResource groupHeaderConverter}}" 
                                Padding="{Binding Level,Converter={StaticResource groupHeaderConverter}}">
                    <Label x:Name="label" Text="{Binding Key}" 
                            FontSize="22"                                   
                            FontAttributes="Bold"                                    
                            VerticalOptions="Center" 
                            HorizontalOptions="Start" 
                            />
                </StackLayout>
            </ViewCell.View>
        </ViewCell>
    </DataTemplate>
</syncfusion:SfListView.GroupHeaderTemplate>

public class GroupHeaderConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (targetType.Name == "Color")
        {
            if ((int)value == 1)
                return Color.Aqua;
            else
                return Color.AntiqueWhite;
        }
        else
        {
            if ((int)value == 1)
                return new Thickness(5, 5, 5, 0);
            else
                return new Thickness((int)value * 15, 5, 5, 0);
        }
    }
 
    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return value;
    }
}