Duke Rabbit's Game Zone

First, We define a nested property class, which is named "Location". And it contains two properties: x, y

ref class Location
{
public:
    float       fX;
    float       fY;

    [DisplayNameAttribute("X"),
        DescriptionAttribute("X Position"),
        DefaultValueAttribute(false)]
    property float X
    {
        float get(void)
        {
            return fX;
        }
        void set(float fValue)
        {
            fX = fValue;
        }
    }
    [DisplayNameAttribute("Y"),
        DescriptionAttribute("Y Position"),
        DefaultValueAttribute(false)]
    property float Y
    {
        float get(void)
        {
            return fY;
        }
        void set(float fValue)
        {
            fY = fValue;
        }
    }
};

Then, we need a type converter to convert the nested property value to detailed value, and vice versa:

ref class LocConverter : public ExpandableObjectConverter
{
public:
    virtual bool CanConvertFrom(ITypeDescriptorContext^ context, Type^ t) override
    {
        if (t == String::typeid) {
            return true;
        }
        return ExpandableObjectConverter::CanConvertFrom(context, t);
    }
    virtual Object^ ConvertFrom(ITypeDescriptorContext^ context, CultureInfo^ info, Object^ value) override
    {
        if (value->GetType() == String::typeid) {
            String^ s = (String^) value;
            int comma = s->IndexOf(',');
            if (comma != -1) {
                Location^   qLoc = gcnew Location;
                String^ qX = s->Substring(0, comma);
                qLoc->fX = float::Parse(qX);
                qX = s->Substring(comma+1);
                qLoc->fY = float::Parse(qX);
                return qLoc;
            }
        }
        return ExpandableObjectConverter::ConvertFrom(context, info, value);
    }
    virtual Object^ ConvertTo(ITypeDescriptorContext^ context, CultureInfo^ culture, Object^ value, Type^ destType)  override
    {
        if (destType == String::typeid && value->GetType() == Location::typeid) {
            Location^ qLoc = (Location^)value;
            return qLoc->fX.ToString("F") + ", " +   qLoc->fY.ToString("F");
        }
        return ExpandableObjectConverter::ConvertTo(context, culture, value, destType);
    }  

};

Final, we put the sub-nested property into main property menu:

ref class Property
{
public:
    Location^       m_qLocation;
public:
    Property(void)
    {
        m_qLocation = gcnew Location;
    }
   [TypeConverter((LocConverter::typeid)),
        CategoryAttribute("Properties"),
        DescriptionAttribute("Location"),
        DefaultValueAttribute(false),
        DisplayNameAttribute("Location")]
    property Location^ Loc
    {
        Location^ get()
        {
            return m_qLocation;
        }
        void set(Location^ qType)
        {
            m_qLocation = qType;
        }
    }

};