How to join hidden wifi with Repeater

It seemed like that in the Repeater just can not scan the hidden wifi, is that right?

Could I add a hidden wifi by input wifi ssid?

i found the way to connect to the hidden wifi in luci, but i can not delete this topic.

I think this was discussed just a few days back but it would be helpful if you could post the fix again or the link that helped you solve it!