if there are 3 nodes namely out1 out2 and out3 whose waveforms you wish to see in a single plot, type
plot v(out1) v(out2) v(out3)
print alli > plot_data_i.txt line in the .cir.out file
Save the file and simulate
You can use the interactive Plotting window that appears after simulation. Select all those nodes for which you wish to see the plots and then click on plot button.