Once a tag is added, it will behave like a variable in the logic within Custom Filters.
If you have a tag pre-populated in the search field, this will appear in the logic. On the other hand, you can add the advanced logic yourself. This advanced filter is available in the open-ended interface; it will globally filter the entire survey and enable you to create a custom report. This logic is also available in the filter icon outside of the open-ended interface allowing you to filter the entire dataset by these tags.