This blog is part of my series Making Data Tell a Story With SSRS Properties.
Property: FixedRowHeaders
The purpose of this property is to show row headers as you scroll across a page to view data.
To access the property, select the tablix and select FixedRowHeaders.
The options are True or False.
Example: I have a matrix that displays order counts and totals by year, grouped by sales region. The Territory Name header appears when I am left-most in the rendered report.
I go to the report and set FixedRowHeaders to True (and the Background Color of the column with the text boxes to white). When I view the report again, and scroll to the right, I see the row at the left at all times.
Further Reading:
Controlling Row and Column Headings (Report Builder 3.0 and SSRS)