using System;   

using System.Linq;  

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

           List<string> countryList = new List<string>() { "Spain_Finance", "France_Sport", "Spain_Politics", "USA_Science", "USA_Finance" };

           string namecountry = "Spain";

           List<string> SelectedCountries = countryList.Where(x => x.Contains(namecountry)).ToList();

        Console.WriteLine("Selected Countries : {0}", String.Join(",",SelectedCountries));

    }

}