First, let's differentiate between Zing ZVM versions and Java SE level. The Java SE level is for example Java 8, or also written as 1.8.0. The ZVM version providing the actual implementation is for example 18.104.22.168.
Both version numbers are part of the ZVM installation path. Here an example: /opt/zing/zing-jdk1.8.0-22.214.171.124-12-x86_64
You can always install and use multiple Java SE Levels each using a different ZVM version.
But if you want to install and use different ZVM versions providing the same Java SE level, you need to use the ZVM tar.gz or .sh installation packages available on https://www.azul.com/software-downloads-and-documents/.
The ZVM RPM and DEB packages always replace the previously installed ZVM version. The tar.gz and .sh packages do not modify any previous installation.