The Dynamic Parameter Actions currently active on a site can be seen on the 'Dynamic URLs' tab where you applied them and also along with the Delete URLs on the 'Actions' tab. You will see all Dynamic Parameter Actions that are applied for the site across all authenticated users of the site.
The effective actions also list the # of URLs that were affected by the Action at the time it was applied. Remember that once the rule is applied the # of URLs you might find with that parameter in the system will reduce and we will not be able to retrieve the original list known at the time of applying the rule.
Note: If the person who requested the Dynamic Parameter Action, changes status, and becomes un-authenticated: