I appreciate you all let me know how to do it. I tried to 3 different way into 1 code, which are value, pointer and reference. Probably still I don't understand them and it's need to be correction in my code, however the compile is pass and I can see what I want to see in the console, so I am grad to it!

//   g++ -o rps.exe rps.cpp

#include <iostream>
#include <random>

int random(int const low, int const high)
{
    static std::mt19937 mt{ std::random_device{}() };
    static std::uniform_int_distribution<int> random_number;
    using param_type = std::uniform_int_distribution<int>::param_type;
    return random_number(mt, param_type{ low, high });
}

class User
{
    public :
        User(){};  //constructor

        int hand;
        void setHand()
        {
            std::cout << "What you choose? (ROCK = 1, SCISSORS = 2, PAPER = 3) := ";
            std::cin>> hand;
        }
};

class Computer
{
    public :
        Computer(){}; //constructor

        int hand;
        void setHand()
        {
            hand = random(1, 3);
            std::cout << "Computer choose := " << hand << std::endl;
        }
};

class Judge_R   //By Reference
{
    public :
        User& user_R;
            Computer& computer_R;

            Judge_R(User& user_R, Computer& computer_R) : user_R(user_R), computer_R(computer_R) {};
        
        void doJudge()
        {
            std::cout << "User CHOSE hand in class Judge_R := " << user_R.hand << std::endl;
            std::cout << "Computer CHOSE hand in class Judge_R := " << computer_R.hand << std::endl;
        }
};

class Judge_P   //By Pointer
{
    public :
        User* user_P;
            Computer* computer_P;
        
            Judge_P(User* user_P, Computer* computer_P) : user_P(user_P), computer_P(computer_P) {};
        
        void doJudge()
        {
            std::cout << "User CHOSE hand in class Judge_P := " << user_P->hand << std::endl;
            std::cout << "Computer CHOSE hand in class Judge_P := " << computer_P->hand << std::endl;

        }
};

class Judge_V   //By Value
{
    public :
        void doJudge(int const user_hand, int const computer_hand)
        {
            std::cout << "User CHOSE hand in class Judge_V := " << user_hand << std::endl;
            std::cout << "Computer CHOSE hand in class Judge_V := " << computer_hand << std::endl;
        }
};

int main()
{
    User user;
    user.setHand();
    //std::cout << " user.hand in main() := " << user.hand << std::endl;

    Computer computer;
    computer.setHand();
    //std::cout << " computer.hand in main() := " << computer.hand << std::endl;

    //By Reference
    Judge_R judge_R(user, computer);
    judge_R.doJudge();
    
    //By Pointer
    Judge_P judge_P(&user, &computer);
    judge_P.doJudge();
    
    //By value
    Judge_V judge_V;
    judge_V.doJudge(user.hand, computer.hand);
}

C:\RPS>g++ -o rps.exe rps.cpp

C:\RPS>rps.exe
What you choose? (ROCK = 1, SCISSORS = 2, PAPER = 3) := 1
Computer choose := 2
User CHOSE hand in class Judge_R := 1
Computer CHOSE hand in class Judge_R := 2
User CHOSE hand in class Judge_P := 1
Computer CHOSE hand in class Judge_P := 2
User CHOSE hand in class Judge_V := 1
Computer CHOSE hand in class Judge_V := 2