Actually i need when click on button 1 on windows form Edit Row
get selected value of combobox1 from windows form Edit Row to windows form Form1

I have two windows form
Form1 (have combobox1 drop down style:drop down list)
Edir Row (I have combobox and button)



Details

form1_load

Code:
var dataSourceAr = new List<Country>();
 dataSourceAr.Add(new Country() { Name = "اختر دوله", Value = 0 });
 dataSourceAr.Add(new Country() { Name = "الاردن", Value = 1 });
 var dataSourceEn = new List<Country>();
 dataSourceEn.Add(new Country() { Name = "SelectCountry", Value = 0 });
 dataSourceEn.Add(new Country() { Name = "Jordon", Value = 1 });
 var combined = dataSourceEn.Join(dataSourceAr, en => en.Value, ar => ar.Value, (en, ar) => new { Value = en.Value, Name = $"{ar.Name} - {en.Name}" }).ToList();
 comboBox1.DataSource = combined;
 comboBox1.DisplayMember = "Name";
 comboBox1.ValueMember = "Value";

public class Country
    {
        public string Name { get; set; }
        public int Value { get; set; }
    }
under button 1 click on windows form Edit Row that i need to pass selected value from it to form1 combobox

Code:
private void button1_Click(object sender, EventArgs e)
        {  
                Form1 frm = new Form1();
                var cb1 = frm.comboBox1;
                var index1 = cb1.FindString(comboBox1.Text);
                cb1.Text = index1.ToString();
                frm.Show();




                
            
        }
Code:
Edit Row load form
// same values and code of  combobox1 in Form1
when click button value of combobox1 from Edit form will transfere to second form Form1

Result of code above

when click button it show form1 but no selection to combobox on form1 as Edit Row form
So that what i do to solve problem ?