To change the grouping variables
main topics      examples 

1    Select and double-click all areas, symbols, project lines, bars, or connect lines. See Selecting groups and single items.

2    Click the Groups tab.

3    In Categorical variables for grouping, enter up to four columns containing categorical grouping variables. Minitab assigns different attributes to each group and displays a legend.

4   If you like, check Apply same grouping to other data displays to assign the group attributes to all data displays on the graph. (Not available with histograms, probability plots, or empirical cdf graphs.)

5    Click OK.