off the top of my mind, if you're able to make a union of the data with itself in the data connection, but in the second part of the union replace your Market dimension with 'Grand total', then you will have the data for the totals as regular data in your dataset. Consequently, you may disable Tableau's native functionality for totals, and just display the plain tables, and your filter action will function properly when you click on the grand total.
One caveat though, the grand total will be independent of your selections of separate markets - e.g. if you select Germany, France and Finland, and the Grand Total, the latter will not reflect the sum of the 3 countries of interest. Therefore you may opt to make the action work only on a single select.
Hope this helps,