TYPO3 Core

If you have nested user groups assign to an editor,
only the first level user group is used to find the relevant recipients for "send to next stage" action.

If you debug the "$userdata" we can see that the user have a lot of groups assigned but only the "usergroup" is used for comparsion.

username     admin
usergroup     21
usergroup_cached_list     26,6,22,20,23,16,3,27,19,17,24,1,8,4,10,5,2,11,13,9,12,7,14,18,21
uid     19

Solution is just to use the field "usergroup_cached_list" to check full list of assigned groups.