How to insert text in two textboxes referring to a DataGridView in C#

Good Morning. It turns out that I have two textboxes in my Windows Forms application, and I need both textboxes to be filled with text from the same dataGridView.

When I click the query button, a DataGridView opens, with the data from the PERSONAL table identified by name and ID. When I click twice on the same row, the id of the person I have selected should be put in the From Operator textBox and I want that when I hit the second Query button (the Until Operator) the same DataGridView opens and selects another operator and it is placed in the Until Operator TextBox .

Here comes the problem, when he opens the second query button and the same DataGridView appears when I select a name, in the from operator textbox it is the same as the one I select to put in the To Operator textbox . I send the code, in case you can help me. Thanks in advance.

private void eCellDoubleClick(object sender, DataGridViewCellEventArgs e)
            {
            // Si el doble click se ha hecho en alguna celda de la cabecera no hacer nada
            if (e.RowIndex == -1)
            {
                return;
            }


            switch ((sender as Control).Name)
            {

                //DataGridView
                case "dgvPersonal":

                    Formulario_Consulta f1 = Application.OpenForms.OfType<Formulario_Consulta>().SingleOrDefault(); //Devuelve un solo elemento en la secuencia

                    if (f1 != null)//o sea el formulario de consulta está abierto y no se ha cerrado
                        {
                            int id_persona = (Int32)dgvPersonal.CurrentRow.Cells[ID_PERSONA].Value; //Sacamos el valor de la id persona correspondiente que al hacer doble click, sobre ella.
                            int id_persona2 = (Int32)dgvPersonal.CurrentRow.Cells[ID_PERSONA].Value; //Sacamos el valor de la id persona correspondiente que al hacer doble click, sobre ella.
                            f1.tb_Desde_Operario.Text = id_persona.ToString(); //y le añadimos al textbox correspondiente el id de la persona para hacer la pertinente consulta
                            f1.tb_Hasta_Operario.Text = id_persona2.ToString();
                            Close(); //Cierro el formulario de consulta del personal.
                        }

                    break;

                default:
                    //...
                    break;
            }
        }