1  with v as (
  2  select 'USD' cur,date '2016-01-01' dat, 20 val from dual union all
  3  select 'USD' cur,date '2016-02-01' dat, 21 val from dual union all
  4  select 'USD' cur,date '2016-05-01' dat, 22 val from dual union all
  5  select 'USD' cur,date '2016-09-01' dat, 25 val from dual union all
  6  select 'EUR' cur,date '2016-01-01' dat, 30 val from dual union all
  7  select 'EUR' cur,date '2016-02-10' dat, 31 val from dual union all
  8  select 'EUR' cur,date '2016-07-25' dat, 32 val from dual union all
  9  select 'EUR' cur,date '2016-09-04' dat, 31 val from dual
 10  )
 11  select * from v
 12* where dat=(select max(dat) md from v v2 where v2.cur=v.cur and v2.dat<=date '2016-09-01')
SQL> /

CUR DAT             VAL
--- -------- ----------
USD 01.09.16         25
EUR 25.07.16         32

SQL> ed
Wrote file afiedt.buf

  1  with v as (
  2  select 'USD' cur,date '2016-01-01' dat, 20 val from dual union all
  3  select 'USD' cur,date '2016-02-01' dat, 21 val from dual union all
  4  select 'USD' cur,date '2016-05-01' dat, 22 val from dual union all
  5  select 'USD' cur,date '2016-09-01' dat, 25 val from dual union all
  6  select 'EUR' cur,date '2016-01-01' dat, 30 val from dual union all
  7  select 'EUR' cur,date '2016-02-10' dat, 31 val from dual union all
  8  select 'EUR' cur,date '2016-07-25' dat, 32 val from dual union all
  9  select 'EUR' cur,date '2016-09-04' dat, 31 val from dual
 10  )
 11  , v2 as (
 12  select v.*
 13   ,row_number() over (partition by cur order by dat desc) rn
 14  from v
 15  where v.dat<=date '2016-09-01')
 16  -----
 17* select * from v2 where rn=1
SQL> /

CUR DAT             VAL         RN
--- -------- ---------- ----------
EUR 25.07.16         32          1
USD 01.09.16         25          1

SQL>

  1  with v as (
  2  select 'USD' cur,date '2016-01-01' dat, 20 val from dual union all
  3  select 'USD' cur,date '2016-02-01' dat, 21 val from dual union all
  4  select 'USD' cur,date '2016-05-01' dat, 22 val from dual union all
  5  select 'USD' cur,date '2016-09-01' dat, 25 val from dual union all
  6  select 'EUR' cur,date '2016-01-01' dat, 30 val from dual union all
  7  select 'EUR' cur,date '2016-02-10' dat, 31 val from dual union all
  8  select 'EUR' cur,date '2016-07-25' dat, 32 val from dual union all
  9  select 'EUR' cur,date '2016-09-04' dat, 31 val from dual
 10  )
 11  select * from v
 12* where (cur,dat) in (select cur,max(dat) from v v2 group by cur)
SQL> /

CUR DAT             VAL
--- -------- ----------
EUR 04.09.16         31
USD 01.09.16         25