Hello, yes you can!
Set up the hAP in AP bridge/station mode (this old topic is usefull for knowing the differences betwen them http://forum.mikrotik.com/t/apbridge-mode-vs-station-mode/131651/1), if in your main router you have the right routing (who can connect to what ecc,) there is no need to make routing configuration in the hAP.
In the hAP you need to bridge all interface (including wi-fi) and the work is done (some usefull information can be found here https://help.mikrotik.com/docs/display/ROS/Bridging+and+Switching).
Edit: This one is a usefull link for the “set up ap bridge/station” → https://help.mikrotik.com/docs/display/ROS/Wireless+Interface#WirelessInterface-Repeater