This modification shows third level of the top categories at menu in a column.
If subcategory of top categories has a subcategory , it will be shown at menu by hover.
See the demo here.

Only for version 3.0 and upper

Install instructions:
1. Go to Admin panel of your store
2. Open Extensions > Installer
3. Press "Upload" button, select downloaded archive, and upload it.
4. Go to Extensions > Modifications, and press "Refresh" button.
Done.

For support: alaskii@mail.ru , Eduard.