A Group Row variable is inserted from version 3.2
Depending on which band is used, this variable will show the current row from the enclosing group. If no group is defined inside report, this variable is identical with Row variable which shows the number of current record.
Using the variable inside an expression like
$V_GROUP_ROW + ". " + $C_First_Name + " " + $C_Last_Namewill show the next result :