With the promptable filters, you can select the data in filters as per your requirement.
For example, Celoxis provides a canned report "My Expenses" which shows you the expenses created by you in the current week (This Week). However, you might want to see the expenses for the entire month; which you can achieve by selecting "This Month" in the "Created" filter.
After viewing the data, you might want to set the report to its default i.e 'This Week'. The Reset option under the report actions lets you revert back to the original filter values.
The option will reset the promptable filters for only that user who clicked on 'Reset'. Rest all will see the Filters as set by them.