Usually the Y and Z column will belong to the X to the closest X column on the left. Origin 2023b allows user to specify which X group it belongs to.
Create a 5 column worksheet. Set column C as X column as well.
? Columns will be broken into two groups. A, B in group 1 and C, D, E in group 2. See the column designation has 1 and 2.
If user select column D to plot, it will use C as X.
In Script window, run wks.col4.group=1 // press Enter key to execute it
? Now D will be marked with D(Y1). If now select column D to plot, it will be plotted against column A as its X.