For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:joeyli:branches:SUSE:SLE-15-SP4:Update_bsc1217251/15.5/home:joeyli:branches:SUSE:SLE-15-SP4:Update_bsc1217251.repo
zypper refresh
zypper install bluez-test
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:joeyli:branches:SUSE:SLE-15-SP4:Update_bsc1217251/15.4/home:joeyli:branches:SUSE:SLE-15-SP4:Update_bsc1217251.repo
zypper refresh
zypper install bluez-test