By default, the Network Detective Application installer creates the applications data directory under the local profile of the logged in user.
If you would like to share the data directory with multiple users on the network you would have to set your data directory to shared location on the network. This can be done by clicking the "Change Data Directory" link from the Home screen of the application.
Any user wishing to access that data would have to set their data directory to that location.
Keep in mind that this will only create the folder structure in the new location, it will not copy the existing files. You will have to manually do that.
The default location of the Network Detective files is %appdata%\Network Detective.