<r:Ribbon.CommandBindings>
    <CommandBinding Command="{x:Static local:MainWindow.ImageBindingCommand}" CanExecute="ImageBindingCommand_CanExecute" Executed="ImageBindingCommand_Executed"></CommandBinding>
</r:Ribbon.CommandBindings>

<r:Button Header="Привязать" ToolTip="Привязять выбранное изображение к команде" Command="{x:Static local:MainWindow.ImageBindingCommand}" LargeIcon="pack://application:,,,/InterfaceImageBinding;Component/Images/Ribbon/navigate_left.png">
    <r:Button.CommandParameter>
        <MultiBinding Converter="{StaticResource ImageBindingSourceConverter}">
            <Binding ElementName="lv_UserImages"></Binding>
            <Binding ElementName="lv_interface"></Binding>
        </MultiBinding>
    </r:Button.CommandParameter>
</r:Button>

public partial class MainWindow : Window
    {
        private static RoutedCommand _ImageBindingCommand = new RoutedCommand();
        public static RoutedCommand ImageBindingCommand
        {
            get
            {
                return _ImageBindingCommand;
            }
        }

        private void ImageBindingCommand_CanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute = (e.Parameter != null && (bool)e.Parameter);
        }

        private void ImageBindingCommand_Executed(object sender, ExecutedRoutedEventArgs e)
        {
        }
    }

public class ImageBindingSourceConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (values.Length == 2 && values[0] is ListView && values[1] is ListView)
        {
            return (values[0] as ListView).SelectedItem != null && (values[1] as ListView).SelectedItem != null;
        }
        return false;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}