remove duplicate in report

remove duplicate in report

Hello,

I want to build a report showing only one instances of the same record.

Example:


There are 3 Walmart in NewYork, 2 in Chicago and 2 in Boston.
There are 2 Target in Seattle and 2 in Teaxs.

I want to see in the report:

Walmart (Grouped by)
NewYork
Chicago
Boston
Target (Grouped by)
Seattle
Texas

And not:

Walmart, NewYork
NewYork1
NewYork2
NewYork3
Walmart, Chicago 
Chicago 1
Chicago 2
Walmart, Boston
Boston 1
Boston 2

thank you