Hi!

SELECT
  TIMESTAMPADD(
       SQL_TSI_DAY
       , 1
       , TIMESTAMPADD(SQL_TSI_DAY
            , DAYOFWEEK(CURRENT_DATE) * -1
            , CURRENT_DATE
       )
   )
  , TIMESTAMPADD(
       SQL_TSI_DAY
       , 7
       , TIMESTAMPADD(SQL_TSI_DAY
            , DAYOFWEEK(CURRENT_DATE) * -1
            , CURRENT_DATE
       )
   )
FROM [YOUR_SUBJECT_AREA]

It was sql-query for OBI.

If you want make dynamic variable, you need use classic sql:

ALTER SESSION SET NLS_TERRITORY = AMERICA;

SELECT TRUNC(SYSDATE) - TO_NUMBER(TO_CHAR(SYSDATE,'D'))
    , TRUNC(SYSDATE) - TO_NUMBER(TO_CHAR(SYSDATE,'D')) + 7
FROM DUAL;

This 'D'-element returns the number of the day of the week (1-7). The day of the week that is numbered 1 is specified implicitly by the initialization parameter NLS_TERRITORY.

The best solution, not to depend on regional settings - you need make table "Calendar", where on each date you can assign day number of week (and week number, and year, and a lot more)

After that, you can get dates using simple query, example

SELECT DATE
FROM CALENDAR
WHERE YEAR = 2016
    AND WEEK_NUM = 24
    AND DAY_OF_WEEK_NUM IN (1, 7)

You have table "Calendar", good.

But the field CALENDAR_DAY_of_the_week filled not as you need

Now you need to fill in the fields of the table so that 26.06.2016 was the first day of week, 02.07.2016 was the seventh day of week (most likely need to use a new column)

This query is dinamical:

SELECT DATE
FROM CALENDAR
WHERE YEAR =  EXTRACT (YEAR FROM SYSDATE)
    AND WEEK_NUM = TO_NUMBER(TO_CHAR(SYSDATE, 'WW'))
    AND DAY_OF_WEEK_NUM IN (1, 7)

You can use Connect By Level to display all the days within current week. you need to find the current week from your Day table in warehouse.

refer these:

List of days between two dates

https://asktom.oracle.com/pls/apex/f?p=100:11:0::::p11_question_id:14582643282111