You can only update to the latest version of a package available in the repositories, whatever that version is.
A few number of applications do provide a stable branch, which translates into a different package – for instance libreoffice-still vs libreoffice-fresh – allowing you to use the package from the associated branch. Updates work exactly the same: you’ll get the latest version of that package as available in the repositories, the only difference being that one comes from a stable development branch.