SQL> ed
Wrote file afiedt.buf

  1  select
  2   dname
  3  ,lag(dname,1,'-') over (order by deptno) l1
  4  ,lag(dname,2,'-') over (order by deptno) l2
  5  ,lag(dname,3,'-') over (order by deptno) l3
  6* from dept
SQL> /

DNAME          L1             L2             L3
-------------- -------------- -------------- --------------
ACCOUNTING     -              -              -
RESEARCH       ACCOUNTING     -              -
SALES          RESEARCH       ACCOUNTING     -
OPERATIONS     SALES          RESEARCH       ACCOUNTING