Multi level drill down

What are the common columns between levels 2 and 3?

There's a level id conected, but no common field between level2 and level3 shown in the report. Right now I use a store procedure to select all data. The selected data include ids of each levels. Thanks.

So, no common columns, which means it's not truly a parent-child set of data, so explain in great detail how this 'drill down' between Levels 2 and 3 would occur.

Sounds more like two different levels of detail.

One store procedure select all data for the report. Each level has relationship with PK/FK.

I build the grouping using the way that is shown in this link http://www.dailymotion.com/video/xspk60_reporting-services-grouping-in-tables_tech

Instead of using id field, I use the name field.

I attached three screen shots: Design time show, preview show and two levels expended show. for the third level, I have not built drill down yet, as I need to know how to do it.
DesignTime.png
ReportShowUp.png
InnerTwoLevelsExpended.png

I attch another design time screen shot which shows the grouping clearly.

'Instead of using id field, I use the name field.' I mean I use each level Name to display in teh report for grouping. In store procedure query, I have selected each id field for all levels.
designtime.png

Great! Thanks for the post. I still need a little more help.

1. I changed the desin time a little. See the yellow circle in attached designtime file.

2. If I set Visibility of Group Properties at group level which is the Red Circle in attached designtime, when I preview the report, I get error:
The grouping 'GName' have 'GName' as a toggle item. Toggle item must be text boxes that share the same scope as the hidden item or are in a scope that contains the hidden item, and cannot be contained within the current report item unless grouping scope has a parent.

3. So I changed to set Visibility of Group Properties at Static level which is the Green Circle in attached, the error is gone, and report shows. Great! See ReportShow file. But the Green Circle one is actually the second textbox. So When I clicked the first bule circle, instead of lower level hidding, the clicked group fields which belong to Static level hide, see the attached ClickedFirstOne file.

I need the lower level hide/show when the higher level is clicked.

I appreciate further help.
designtime.png
ReportShow.png
ClickedFirstOne.png

You're changing the Visibility settings for the wrong group.  The one indicated with the red circle is the top group, you don't want to hide/show that one.  Instead of that, you should be setting the Visibility settings for the second yellow item in the Row Groups window.

How to set Visibility settings for the second yellow item in the Row Groups window? This is what I'm looking for.

See the file designtime, the Row Groups window has title group and static group (red and green).  I have set either of the two, it does not work correctly.

I know I did not set Visibility settings on correct row. If I set Visibility at the lower level from the first cell of table row, which is the second row in yellow circle, the drill down works quite wrong. I can only set Visibility from Row Groups window. But where is it in Row Groups window?

See attach, I added a blue circle.
designtime.png

Great Solution!