Mass Update records of Dynamic Group Members

As Administrator navigate to Lists > Mass Update > Mass Updates > General Updates > Contact > Criteria Tab > add filter Group. Notice that only Static Groups are showing on the list of Group.

1. Navigate to List > Relationships > Groups > View any Dynamic group > click name of the Saved Search linked to the group. 
2. Edit the saved search to check filters Added under Criteria tab.
3. Use the criteria filters of the saved search when mass updating records via Lists > Mass Update > Mass Updates > General Updates > Contact > Criteria Tab.