IF you come from autotools background, you will be familiar with --bindir, --libdir, --sbindir etc parameters passed to configure script that allow for fine tuning the installation layout. A similar functionality is available with CMake build too.
CMAKE_INSTALL_PREFIX: specifies the "root" directory of the installation, same as autotools --prefix
INSTALL_BINDIR, INSTALL_SBINDIR, INSTALL_LIBDIR: correspond to autotols
--bindir, --sbindir, --libdir parameters. A subtle difference is that INSTALL_XXXDIR should be paths relative to CMAKE_INSTALL_PREFIX, e.g INSTALL_BINDIR should be "bin" rather than "/usr/bin".
there is INSTALL_LAYOUT parameter that allows to choose one of several predefined installation layouts
STANDALONE with layout is the same as in tar.gz/zip packages
RPM with layout similar to RPM packages - for example mysqld is in sbin subdirectory.
SVR4 - Solaris package layout
DEB (experimental)- Layout as in DEB package
Default layout is STANDALONE.
Here is an example on how to modify STANDLONE layout slightly and install libraries into "lib64" subdirectory instead of default "lib"
cmake . -DINSTALL_LAYOUT=STANDALONE -DINSTALL_LIBDIR=lib64