How to sort a Reporting Services table by an auto generated column-Collection of common programming errors

You can sort by any sort of expression – SSRS will quite happily sort something like two fields concatenated together:

=Fields!Class1.Value & Fields!value.Value

Just be careful to make sure the sorting is applied at the appropriate level to avoid unexpected, i.e. make sure you don’t have different sorting expressions in any row group or detail group if not required.

If No Vencido is the grouping expression, apply the sorting at the group level.

If you don’t want to sort on an expression, you can create a calculated field for each row in the dataset with the expression =Fields!Class1.Value & Fields!value.Value and group/sort on that calculated field as required.

Edit after comment

OK, I think you need to apply a sort expression like this to the groups that apply to the Top and Otros rows:

=Sum(IIf(Fields!Clase_1.Value = "No Vencido", Fields!Monto.Value, Nothing))

This is still sorting by the total Monto for each row group, but only considering the rows where Clase_1 is No Vencido.

Once this is set up sort by A-Z or Z-A as required.