static void Main(string[] args)
var filters = new[] { "txt files (*.txt)|*.txt|All files (*.*)|*.*", "Image Files|*.jpg;*.jpeg;*.png;", "Excel Files (*.xls, *.xlsx)|*.xls;*.xlsx|CSV Files (*.csv)|*.csv" };
foreach(var filter in filters)
var extensions = filter.Split('|', StringSplitOptions.RemoveEmptyEntries)
.Where((x, i) => i % 2 != 0)
.SelectMany(x => x.Split(';', StringSplitOptions.RemoveEmptyEntries))
.Select(x => x.TrimStart('*'))
Console.WriteLine(string.Join(" ", extensions));