Hotspot WiFi (built-in) to WiFi (usb wifi card), how to? I'm trying to share my wifi connection with to-link TL-WN725N. 
I've found the drivers and its works and I connect to WiFi with this or AirPort in the same way (for the first I use Wireless Network Utility).

I can share from USB Wifi Card -> Wifi Built-in with Connection Shared in Systems Preferences but it doesn't work in the other way (Wifi -> Usb Wifi Card).

Have you any idea how can I do this?

The problem to use WifiCard -> Wifi is that the Card is slower than AirPort and, while the shared connection can be slowly, the connection on mac can't be slow, so I need to connect Mac with AirPort and share with Usb Wifi Card.
Your build in WiFi card can only work one way.

So if it is receiving the WiFi than it can not broadcast (share) it at the same time.

But if your Internet connection comes in via USB WiFi or cable then you can use the build in WiFi to share (it is sending).