The harmonic cursor settings are available from a pop-up menu in the spectrum window. This cursor also has the ability to move between the lines of resolution. Do this by pressing and holding the SHIFT key while you press the arrows. This behavior is also explained on this pop-up window:

1) Right-click inside of a spectral plot

2) Select "Setup Options"

3) From the center of the new window, check the box for "Harmonic Cursor for Spectrum Plots"

4) Enter a value for the "Number of harmonics to display

5) Click "OK" to close the window

6) Return to the spectrum and move the cursor with either the Arrow keys or the SHIFT+Arrow keys

See the attached video for a short demonstration