I have installed firmwares typing install-wifi-firmwares.sh, but I can’t see available networks.
What adapter does the G530 come with, is it in our list of supported hardware?
A first thing, this script is there only for few old drivers because at that time firmware licenses didn’t allow redistribution. So if you don’t have hardware that needs such driver, it will do nothing but pollute your system.
Now concerning your problem, if you don’t indicate which version of Haiku you are using nor what is the wifi chip that you want to use, it will be difficult to guess.
It is BCM4312 802.11B/G LP-PHY. Haiku R1/beta4 (rewizja hrev56578+87)x86_gcc2.
It is unsupported, replace it with a supported one or get a supported USB WLAN dongle.