First, click the "Search" button at the top left of the table. Next, you'll be able to click in the drop-down menu at the top of the "Tags" column in your table.
This will show you the full list of tags that you have created. You can filter by one tag or multiple tags. Simply check the box next to the tag(s) you want to filter by. You can also filter by applicants that have no tag.
Click out and your table will automatically update.