I can't understand why you want to use join instead of subselect.
But, you might use following query.
select  A.UNITCOMMON_ID,
       A.POLICY_ID,
       A.LOGICAL_ENTITY_ID,
       A.VERS_ORIG_MAJ_MIN,
       A.ROW_ACTIVE_STS_D,
       A.COMPANY_ID,
       A.PRODUCT_ID

from    POL_UNITCOMMON   A,
       POL_UNITCOMMON_V B,
       TABLE
       (
        select  max(I.VERS_CNTL_MAJ_MIN) AS MAX_VERS_CNTL_MAJ_MIN
          from  POL_UNITCOMMON_V I
         where  I.UNITCOMMON_ID      = B.UNITCOMMON_ID
           and  I.VERS_CNTL_MAJ_MIN <= 0
           and  I.ROW_ACTIVE_STS_D  <= 9999999
           and  (A.LOGICAL_TABLE_C  = 'PPU' or A.LOGICAL_TABLE_C  =
'CPU')
       ) C
where   A.POLICY_ID         = 11
 and   A.UNITCOMMON_ID     = B.UNITCOMMON_ID
 and   B.DELETED_F         = 'N'
 and   B.VERS_CNTL_MAJ_MIN = C.MAX_VERS_CNTL_MAJ_MIN

Why do you want to do that?  You're supposed to write the query in a way you
like and DB2 is supposed to generate the most efficient access plan,
regardless of the way the query is written.

Personally, I'd write the query that way:

SELECT a.unitcommon_id, a.policy_id, a.logical_entity_id,
      a.vers_orig_maj_min, a.row_active_sts_d,
      a.company_id, a.product_id
FROM   pol_unitcommon AS a
WHERE  a.policy_id = 11 AND
      a.logical_table_c IN ( 'PPU', 'CPU' ) AND
      EXISTS ( SELECT 1
               FROM   pol_unitcommon AS b
               WHERE  a.unitcommon_id = b.unitcommon_id AND
                      b.deleted_f = 'N' AND
                      b.vers_cntl_maj_min =
                         ( SELECT MAX(i.vers_cnt_maj_min)
                           FROM   pos_unitcommon_v AS i
                           WHERE  i.unitcommon_id = b.unitcommon_id AND
                                  i.vers_cntl_maj_min <= 0 AND
                                  i.row_active_sts_d <= 9999999 ) )

There I see directly that only data from a single table is requested.  The
rows are restricted based on the subquery in the EXISTS predicate, which
could also be phrased as a non-correlated subquery using "a.unitcommon_id
IN ( SELECT b.unitcommon_id FROM ... )"