Your understanding is correct. It’s the same as the first 3 examples in the Glob Expressions examples in the table below:
https://www.logicmonitor.com/support/terminology-syntax/glob-expressions#:~:text=Production/!(Network/Servers)-,Specifying%20Groups%20with%20Glob%20Expressions,-Resource%20groups%20can
Since the group field supports the use of Glob expressions, it helps with covering many use cases around Alert Rule inclusion/exclusion of groups, some examples are listed in the above article as well