select ltrim(max(sys_connect_by_path(plc_nm, ', ')), ', ') plc_nm
  from (select plc_nm,
                row_number() over(order by regexp_replace(PLC_NM, '[url=http://www.orafaq.com/wiki/:space:]:space:[/url]', '')) rnum
           from (
                 select distinct *
                   from (
                          SELECT a.PLC_NM,
                                  a.busi_deal_no
                            FROM TB_USE_PLC           a,
                                  tb_seal_ri_prms_detl s
                           where a.use_plc_seq = s.use_plc_seq
                             and s.busi_deal_no(+) = '10'
                             and s.busi_detl_seq(+) = '1'
                          union all
                          SELECT a.PLC_NM,
                                 a.busi_deal_no
                            FROM TB_USE_PLC             a,
                                 tb_unseal_ri_prms_detl s
                           where a.use_plc_seq = s.use_plc_seq
                             and s.busi_deal_no(+) = '10'
                             and s.busi_detl_seq(+) = '1'
                          union all
                          SELECT a.PLC_NM,
                                 a.busi_deal_no
                            FROM TB_USE_PLC      a,
                                 tb_rg_prms_detl s
                           where a.use_plc_seq = s.use_plc_seq
                             and s.busi_deal_no(+) = '10'
                             and s.busi_detl_seq(+) = '1'
                          )
                  ORDER BY REGEXP_REPLACE(PLC_NM, '[url=http://www.orafaq.com/wiki/:space:]:space:[/url]', '')))
 start with rnum = 1
connect by prior rnum = rnum - 1