Here is the code. PD_ID is the Key for the table and PARENT_PD is the
parent id for the PD_ID key.
If the record is a parent, then PARENT_PD = -1.

Thanks for the help.

create procedure get_parent
RETURNS (
p1 INTEGER,p2 INTEGER
)
AS

DECLARE VARIABLE pdid INTEGER;
DECLARE VARIABLE pdid_new INTEGER;
DECLARE VARIABLE parentpd INTEGER;
BEGIN

for select l.pd_id, l.parent_pd from pd_list l where
pd_origin = 4 and
not exists ( select p.pd_id from pd_duty_stmt p where l.pd_id=p.pd_id)
into :pdid, :parentpd do begin

p1 = :pdid;
WHILE ( :parentpd != -1 ) DO BEGIN
select parent_pd, pd_id from pd_list where pd_id = :parentpd into
:parentpd, :pdid_new;
p2=:pdid_new;
end
SUSPEND;
end

end