Question : Expand all toggle items in SQL Reporting Services Report

Is there some way to allow the user to expand all items displayed in a report that are collapsed by default when a report generates?

Answer : Expand all toggle items in SQL Reporting Services Report

According to Bruce Johnson at MS, SQL:RS SP1 does not currently support a 'Expand/Collapse All' toggle, though it is on their feature wish list for future versions.

I have seen a workaround that might work, which is based upon creating an extra parameter within the report that is used as an 'Expand All' for the users:

Quote from Chris McGuigan:
"I've done this by adding a parameter to say expand yes or no, in your scenario, default it to no. In the Visibility tab of the drill down level (Right click group line, and choose 'Edit Group'), I use an expression in the 'Initial visibility' section to return true or false depending on the parameter value. This way the user can expand all items at will by change the parameter and pressing 'View report'.

I've taken this further in a report with three drilldown levels. The parameter has four options, no expansion, expand level 1, expand level 2 etc. and then check this parameter in each groups visibility tab.  This is the expression for one of the groups, if it evaluates to True it hides the group.
= (Parameters!ExpandRows.Value<1)"