I think you are specifying wrong base directory in ttt.Extract(filePath3).This file path should be "folder" not folder/folder.
Lets Suppose you zip file resides inside C:\Test and filename is MyZipFile.zip.
using (ZipFile zip = ZipFile.Read(@"C:\Test\MyZipFile.zip"))
foreach (ZipEntry zipEntry in zip)
So base directory should be C:\Test as Extract here will extract into the same folder.