You can not directly export the data from the plotting widget. Instead, you need to use some of the Python methods available for the analysis object.
First, have a looks at the documentation for the InelasticTransmissionSpectrum:http://docs.quantumwise.com/manuals/Types/InelasticTransmissionSpectrum/InelasticTransmissionSpectrum.html (http://docs.quantumwise.com/manuals/Types/InelasticTransmissionSpectrum/InelasticTransmissionSpectrum.html))
With the saved data loaded as
iets = nlread("....nc", InelasticTransmissionSpectrum)[0]
the methods that return the data that is plotted are
inelasticCurrent
inelasticConductance
elasticCurrent
elasticConductance
inelasticElectronTunnelingSpectroscopy
The bottom plot, with "IETS (1/V)" on the y-axis, simply plots the inelasticElectronTunnelingSpectroscopy / inelasticConductance.