If you select projects for swimlanes we will group all fix-versions by projects (1-to-1 relationship). We will also outline all the virtual versions and all the packages as 2 additional swimlanes at the bottom of the roadmap.
In case you organize swimlanes by packages you can sort them
To do so pick up suitable sorting option in the pullup closed to Project/Packages dropdown.
Any package swimlane could be expanded or collapsed individually or all together using controls on the top bar.