R12: Checklists - approval action types

 Hi, having explored checklists, it seems that the only approval action types usable to build a list of recipients is groups;  there seems to be a dynamic or static options when building the groups;  has anyone done anything with supervisor hierarchy and managed to get this working?  e.g. if new hire created, send task to new hire's supervisor (assuming a supervisor is placed on the record at the time of creation).  Any ideas / thoughts would be great, thanks.