With the introduction of variables to bind the current group and current-grouping key, there is some confusion in the spec about whether the terms "current group" and "current grouping key" refer to the underlying concepts whether exposed using the accessor functions or the bound variables, or whether they are only applicable when the accessor functions are used. For example, the description of grouping algorithms/methods uses the terms generically, but the actual definition of the terms is specific to the use of the accessor functions.
The WG decided this issue is editorial and the editor should fix it.
This one proved tricky. I have used "current group value" and "current grouping key value" for the two values regardless whether they are bound to variables or maintained in the dynamic context, and "current group" and "current grouping key" for the values held in the dynamic context.