*QUESTION:
How to create dynamic sorting on Cognos reports?


*ANSWER:
The dynamic sorting isn't part of Cognos Report feature. However, there is a way to configure such settings. Please note that this technique requires the use of undocumented and unsupported capabilities in IBM Cognos BI.

Please see the link below for dynamic sorting configuration.
https://www.ibm.com/developerworks/data/library/cognos/reporting/scripting_techniques/page515.html