CSS Lists and Counters says that an originating element that is a pseudo-element needs to be explicitly specified in the selector. For example, ::marker does not select ::before::marker.
CSS View Transitions says that all of the view transition pseudo-elements are selected from their ultimate originating element, the document element.
For example, ::view-transition-group(*) selects all ::view-transition-group() children of ::view-transition.
A ::view-transition-group() pseudo-element is generated for each view transition name as a child of the ::view-transition pseudo-element
When a pseudo-element participates in a pseudo-element tree, its originating pseudo-element is its parent.
And ::view-transition::view-transition-group(*) is currently invalid in Chrome. Should it be valid?
Maybe the note from CSS Lists and Counters should not apply to functional sub-pseudo-elements?