1.
Select Help > Sample Data Library and open Cities.jmp.
2.
Select Graph > Graph Builder.
3.
Select State and drag it to the X zone.
4.
Select Region and merge it into the X zone. See Region Merged with State.
This makes Region a supercategory, so that states are grouped within Region.
Region Merged with State
5.
Select POP and drag it to the Y zone.
7.
Select Region and drag it to the Color zone.
8.
City Populations by State Grouped within Region

Help created on 9/19/2017