Guessing a bit, for moving a shop into a subdirectory one uses the Base URL, not Virtual URL
Let’s assume your web server serves stuff at /var/www/. Then you install the test shop in /var/www/testshop/. This makes Base URL testshop/ and the shop is available at http://localhost/testshop/. A Virtual URL is needed if you want to access the same shop at http://localhost/testshop/clothes/.
It’s a bit complicated. There are quite a number of possible combinations of installation location and access URL and thirty bees implements all of them.