How to calculate First Date of Posting Period in BEx Query

Question

Hi,
         I have  2 reporting requirements as follows:
1) User will either enter a single posting period in a fiscal year or can enter a range of posting periods.
Based on user selection I need to display three key figures in a report.
Key figure 1 and Key Figure2 should be the summarized values for each posting period.
key Figure 3 should be the value on the first date of that particular posting period (in case user selects multiple posting periods i should derive the value of the first date of each posting period).
2) Also, in another report I need to display only top 8 values  for one key figure in the report.
Please let me know the method or code required to get this Functionality.
Thanks in advance.

Answer 1

First Report
1. Create Restricted KeyFigure 1 & 2 for the summarized values.
2. Create a Customer Exit Variable for getting the first date of the posting period, this should be of type Interval. Write code using FM FIRST_DAY_IN_PERIOD_GET to get. Read the selection variable to see the range of posting period and you have to insert that many first dates into this variable.
3. Create a new Restricted KeyFigure 3 and use the Customer Exit variable created in Step 2
Second Report
Use the Top N functionality of BEx and create a workbook. You can set the option Refresh query when the workbook is open so that the data is current when opened.
Hope this helps.