To block mentions from a specific country, click on:
If you wish to exclude mention from a specific country:
Edit query > Global filters > Location > Exclude... > write in the name of the country you wish to exclude.
If you wish to include mention from a specific country:
Edit query > Global filters > Location > Include... > write in the name of the country you wish to include.
Note:
If you choose to edit the query, we would advise making sure you extracted your data in a form of a document or report prior to making a change because by editing the query you're restarting the search.