You can use the built-in functions
Count() and RowNumber() inside the scope
of the row group
. If the count of the items in the group is equal to the current row number, this means you are positioned at the last row of the group where the bottom border should be.
In your case, the selected textbox (from the attached screen shot) should contain a conditional formatting rule with the following settings:
Expression: = Exec('rowGroup', Count(Fields.PartNumber)) //note: change the rowGroup with the current name of your group
I also attached a sample report that demonstrates the approach. It is created with the Standalone Report Designer and could be opened with version R1 2019 or higher. I hope it helps.
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items