Node groups inherit classes, class parameter values, variables, and rules from parent node groups. More specifically, inheritance works as follows:
Note: If you use different values when classifying a node with the same class, parameter, or variable in another node group that shares inheritance, a conflict occurs. This conflict will cause the next Puppet run to fail. To see the classes and variables that have been assigned to a node through other node groups, in the PE console, go to Inventory, click the node you’re interested in, and go to the Classes or Variables tab.
Tip: You can use the group children endpoint to review group lineage.