I don't know if you can do it with the built in file browser but the screenshot you posted is for the package manager. The package manager just lets you install system packages (application) that the OS and your sites can you. You would need to use a file browser or the terminal to go to the path /var/www/on_this_domain_folder.com/ and run an unzip command. Do a google search for "ubuntu unzip from terminal" (replace ubuntu with whatever OS your server is using).