1. Define the IP address range for clients on the router where shaping is done (if shaping is not done centrally).
2. Do not set up this router as an access point. Set up the UBNT router to which a client is connected as an access point.
3. Select the shaper in the QoS doing on router item in the UBNT router settings.
4. Then you can check the MAC filter box (only monitoring --> active) and the Use wireless MAC filter box.
5. Choose an appropriate access point in the Internet service settings.
6. The MAC filter is applied to the UBNT router and the client in question is assigned to this router.