SSRS one toggle item for expanding multiple groups

Question

i have an SSRS (2008 R2) report with matrix which contains multiple row groups. I need to expand all other groups while having only one toggle item for that. I Hide all necessary groups, and set toggle item the textbox i need. It works great in VisualStudio, but hen i export everything to excel, each group has it's own toggle item. Any idea why?

Some samples. Initial report view:

+------------+----------+------+
| Inst. Name | District | Town |
+------------+----------+------+
| Name 1                       |
+------------+----------+------+
| Name 2                       |
+------------+----------+------+

Report after clicking on institution name (District and town are two different groups):

+------------+----------+-------+
| Inst. Name | District | Town  |
+------------+----------+-------+
| Name 1     | Dist 1   | Town1 |
+            +----------+-------+
|            | Dist 2   | Town2 |
+------------+----------+-------+
| Name 2                        |
+------------+----------+-------+

Answer 1

Reporting Services can render a report in a number of different formats, including "Interactive" (online), PDF and Excel. When you a preview a report in Visual Studio, you are seeing it as it would look in Interactive (online) format. Excel is a very different format and the RS Excel rendering engine attempts to use Excel features to produce an approximation of the online format. For example, the "toggle visibility" feature you are using for the District and Town groups is simulated using Excel grouping. However the behaviour of this Excel feature is not identical to that of the RS feature, which is why each group in Excel will have it's own toggle button.