.NET Fiddle

CSharp · Console

/Program.cs

using System;
using System.Linq;
					
public class Program
{
	public static void Main()
	{
		string input = "This,is,an,example,for,the,stackoverflow,community";
		
		var output = input.Split(",")
			.Chunk(2)
			.Select(chunk => string.Join(",", chunk));
		
		foreach (string s in output)
			Console.WriteLine(s);
	}
}