How to use buttons to control the focus of other buttons？

Question

I want to use the following four direction buttons to control the focus of the above nine buttons, but after a search, this problem has not been solved, so I come to stackoverflow and hope to get an answer.

Thank you for your answers. Forgive me for being a C# beginner.

Answer 1

private Button[,] btns = new Button[3,3] {
                           {button1,button2,button3},
                           {buttonQ,buttonW,buttonE},
                           {buttonA,buttonS,buttonD}};
private int x=0, y=0;

private void buttonLeft_Click(object sender, EventArgs e)
{
    if(y>0)
    {
        y--;
        btns[x,y].Focus();
    }
}

private void buttonRight_Click(object sender, EventArgs e)
{
    if(y<3)
    {
        y++;
        btns[x,y].Focus();
    }
}

private void buttonUp_Click(object sender, EventArgs e)
{
    if(x>0)
    {
        x--;
        btns[x,y].Focus();
    }
}

private void buttonDown_Click(object sender, EventArgs e)
{
    if(x<3)
    {
        x++;
        btns[x,y].Focus();
    }
}