Since cloning a specific folder can be a quite convoluted process via git, you can checkout the Assets/CameraMultiTarget folder directly to your project using SVN: Add the CameraMultiTarget component ...
git-as-svn emulates Subversion repository on top of Git repository. It allows you to work with Git repositories using any tool compatible with Subversion 1.8+: console svn, TortoiseSVN, SvnKit, ...