using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        var filterJson = "name=\"name\";value=\"a\"b\";parameter=\"p1\";value=\"cd\"";

        filterJson = Regex.Replace(filterJson, "value=\"([^\"]+)\"", "value=\"$1\"", RegexOptions.IgnoreCase);

        Console.WriteLine(filterJson);

        var col = Regex.Matches(filterJson, "value=\"([^\"]+)\"");

​

        // Copy groups to a string[] array

        string[] fields = new string[col.Count];

        for (int i = 0; i < fields.Length; i++)

        {

            fields[i] = col[i].Groups[1].Value; // (Index 1 is the first group)

        }// Match all quoted fields

    }

}