There is no button to create a version in MDS. Instead, a version may only be created by copying another version.
Version configuration settings
By default it is only possible to copy a version once it has been committed. This may be fine for some implementations, but prevents you from running two open versions side-by-side. Thankfully, there is a configuration setting that overrides this behavior. The setting is called Copy Only Committed Versions and can be accessed via the MDS Configuration Manager.
The process of copying a version quite simply takes all the members that exist within the source version and copies them into the new version. The supporting structures that the copied members ...