Hi @Rick5,
As it stands we don’t have a filter option for tags, but you should be able to achieve this with the Advanced Search.
Here is an example of a query I ran into one of my project for “Test 1” Tag:
Once you’ve run your search, you can save it in your Report to quickly access it later on. the Report will automatically update has you add this Tag to other tasks in this project.
Hope this helps!