I don't want a hierarchical REFERENCES clause (I am not even sure what that would mean) . But by putting the nodes in one table that reference and the nodes in a separate table, I can have several structures. So one table might be "Personnel" for the company as a whole and then would have a second table that aggregates the employees into "baseball teams", particular projects or whatever. This has the advantage that when an employee is removed from the company, this will also cascade over to the baseball teams, project teams, or whatever. The best way to do this is an ON DELETE SET NULL or ON DELETE SET DEFAULT subclause, but it means you had to do the subordinate hierarchies with careful declarations.
Please post DDL and follow ANSI/ISO standards when asking for help.