One problem that you'll run into is that your tie, behind the scenes, is writing the contents of the top level hash elements to a file. That's similar to printing the top level element. Your top level elements contain hash-refs. When you print a reference, it stringifies the reference and prints that to the file rather than dereferencing the reference and storing it hierarchically in the file. So your suspicions are correct that a tie is not multi-dimensional, unless you somehow concoct a tied class that handles the complexities of dismantling and reconstructing the data structure for you.