Probably the most important thing in Reporting Services is the ability to use expressions for any property of the object. Combine this with the ready-made Previous function, which allows you to access the previous field value, and you have a solution.
Select the entire Detail row. Expand the BorderStyle property and enter the following code for the Top property (if we want the line to separate all departments):
=IIF(Previous(Fields!Department.Value) <> Fields!Department.Value, "Solid", "None")
This compares the previous value of the Department field with the current value, and if it is different, then the upper border of this line will be solid.
Although this puts the line on the top line of the next group and not on the bottom line of the previous group, it is visually and functionally equivalent to what you do after you really easily implement it.
source
share