Reference of 2D-NMR spectra with the 1D external trace

Press the 'R' key (or follow the menu 'Analysis/Reference/Graphic Reference') to activate the Graphic Reference feature. Next click on the peak that you want to reference and finally click again on the new chemical shift (matching with the peaks of the external traces):

To apply an automatic referencing, right click over one of the traces and select 'Setup' to display the 'Setup Traces' dialog box. Once there click on the 'Use External 1H Trace as Reference' box':