After some break this done when looks that driver problem as it worked in Suse Leap 42.3:
1) Install Suse Leap 15 with Gnome desktop
then connect with wire to network
2) Run all updates from Yast (additional: if you have extra hardisk clone spare backup to make easy to start again possible)
3) open YAST -> open software management and remove package b43-fwcutter (allow
also removal of pullin-pcm43xx-firmaware when b43-fwcutter removed
4) Open web browser and open software warehouse:
https://software.opensuse.org/
and use its search too find b43-fwcutter (show all versions) and select openSUSE Leap 42.3 version of b43-fwcutter and start 1-click istallation on web page.
5) After installation b43-fwcutter of openSUSE Leap 42.3 is in use.
6) Restart computer
7) Run install_bcm43xx_firmware in terminal
>sudo /usr/sbin/install_bcm43xx_firmware
8) restart computer; now wlan icon is visible but connection to network fails.
9) pullin-pcm43xx-firmaware of openSUSE Leap 42.3 must be removed ( use YAST )
10) open software warehouse (
https://software.opensuse.org/) and search pullin-pcm43xx-firmaware and install openSUSE 15 pullin-pcm43xx-firmaware version with start 1-click istallation.
11) Run install_bcm43xx_firmware in terminal
>sudo /usr/sbin/install_bcm43xx_firmware
12) Restart computer
13) After restart check from terminal
>dmesg|grep -i b43
..on output should be line with "Loading firmware version 666.2"
14) Now wlan icon is visible and connection also happens and browsing of web
works as it should (fast)
It looks that new latest b43 (784.2 ?) firmware of Suse 15 fails but older of Suse leap 42.3 (666.2) works.
Thank to all that earlier helped in this question.