For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:perl:CPAN-R/openSUSE_Tumbleweed/devel:languages:perl:CPAN-R.repo
zypper refresh
zypper install perl-Regexp-Assemble
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:perl:CPAN-R/15.5/devel:languages:perl:CPAN-R.repo
zypper refresh
zypper install perl-Regexp-Assemble
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:perl:CPAN-R/15.4/devel:languages:perl:CPAN-R.repo
zypper refresh
zypper install perl-Regexp-Assemble