how do I filter data from gridview which is binded by dataset?

public DataSet Ds
            {
                get
                {
                    object temp = ViewState["Ds"];
                    return temp == null ? null : temp as DataSet;
                }
                set
                {
                    ViewState["Ds"] = value;
                }
            }
    
            public void gridCustBind(int pageIndex)
            {
                try
                {
                    //open the db connection if it is closed...  
                    if (connection.State == ConnectionState.Closed)
                        connection.Open();
                    command = new SqlCommand();
                    command.CommandText = "sp_Get_CustInfoSerach";
                    command.CommandType = CommandType.StoredProcedure;
                    command.Connection = connection;
                    command.Parameters.AddWithValue("@PageIndex", pageIndex);
                    command.Parameters.AddWithValue("@PageSize", int.Parse(ddlPaging.SelectedValue));
                    command.Parameters.Add("@RecordCount", SqlDbType.Int, 4);
                    command.Parameters["@RecordCount"].Direction = ParameterDirection.Output;
    
                    //SqlParameter outParam = command.Parameters.Add("@bal", SqlDbType.Float);
                    //outParam.Direction = ParameterDirection.Output;
    
                    command.Parameters.Add("@bal", SqlDbType.Int, 4);
                    command.Parameters["@bal"].Direction = ParameterDirection.Output;
    
                    SqlDataAdapter daAcc = new SqlDataAdapter(command);
                   
                    daAcc.Fill(Ds);
                   }
                catch (Exception ex)
                {
                    lblMessageCustSerach.Text = ex.Message;
                    lblMessageCustSerach.Visible = true;
                }  
                        finally //Close db Connection if it is open....  
                {
                    if (connection.State == ConnectionState.Open)
                        connection.Close();
    
                }
            }        
    
            protected void Page_Load(object sender, EventArgs e)
            {
                if (!IsPostBack == true)
                {
                   
                    gridCustBind(1);
                    if (gridCustomer.Rows.Count > 0)
                    {
                        gridCustomer.DataSource = Ds;
                        gridCustomer.DataBind();
                        
                    }
    
                }
            }