how do I disable recursive search in nautilus 3.6
At the moment it doesn't seem like you can revert back to the nautilus 3.4 behaviour. There's a bug report here.
In the meantime you can install nemo, a fork of nautilus 3.4, that integrates seamlessly with the Ubuntu desktop. To install:
sudo add-apt-repository ppa:gwendal-lebihan-dev/cinnamon-stable
sudo apt-get update
sudo apt-get install nemo nemo-fileroller