Define Last Month as default value for prompt based on dimensional datasource

Hi,

I need to set Last month as a default selection in the value prompt using DMR model in Cognos 10.2.1.

Use Value: [AB DMR].[All Dates].[Date].[Month]
Values are like: 2017/JAN, 2017/FEB, 2017/MAR.....

For Sorting, we used Month Key column.

Can anyon...