if c:\folder1\folder2\folder3\bin is the path then the following code will return the path base folder of bin folder
//string directory=System.IO.Directory.GetParent(Environment.CurrentDirectory).ToString());
string directory=System.IO.Directory.GetParent(Environment.CurrentDirectory).ToString();
ie,c:\folder1\folder2\folder3
if you want folder2 path then you can get the directory by
string directory = System.IO.Directory.GetParent(System.IO.Directory.GetParent(Environment.CurrentDirectory).ToString()).ToString();
then you will get path as c:\folder1\folder2\