1.) Enable rpmfusion free and non-free repositories, see Configuration - RPM Fusion
sudo dnf install https://mirrors.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm https://mirrors.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm
2.) sudo dnf install broadcom-wl, see broadcom-wl | Package Info | koji
3.) reboot
Further information: Broadcom wireless - ArchWiki
edit: @memento : I moved your post into a new topic, since your question is unrelated to the problem the OP was facing with a newer generation wifi chipset.
And, by the way, there is a bunch of similar or same topics on the forum: Search results for 'broadcom' - Fedora Discussion