Test Studio 2012 had filters at the top of each column in the Add Test-as-step dialog. You could filter on name, path, description and so forth. In the new 2013 R1 these filters no longer exist. You can only search by name.

This is a big problem for customers with large test projects. They need more filtering capability, such as by path or owner, to be able to locate the one test they want out of something like 2200 tests. By name is insufficient.