create procedure TEST
returns (...)
as
begin
  for
  select
  as cursor ST
  do
  begin
    with recursive S(...) as
    (
      select ... from T where ID = :ST.ID
      union all
      select ... from T
      inner join S where ID = T.PARENT_ID
    )
    select ... from S
    into ...
    do
    suspend;
  end
end