This dropdown allows you to display data on views depending on the current application's version.
Once your package reaches a new version and anybody installs it on any machine, that new version will be shown in this dropdown. Here, you will have the option to select individual versions for viewing or all versions by selecting the 'All versions' option.
You can only select one version at a time.
Please note that the values displayed here are influenced by the choices you make in the Version Grouping filter.