You can choose a different installation directory apart from the default one using the client install setting. But you  can not change the installation directory for every user using the same package.

Cheers,
Aniket

The installation mode for per-user or per-machine installation is set by the ALLUSERS property.

Assuming your installation folders are linked to the INSTALLDIR directory property, you can use two Set Directory custom actions to set INSTALLDIR to the desired paths for each of these install modes.
You would then use the ALLUSERS property as a condition on each custom action, to control which one runs. So for a per-machine install, the set directory custom action condition would be ALLUSERS=1 for the custom action that sets the per-machine install path, and for a per-user install, you might choose the condition ALLUSERS<>1 or alternatively, ALLUSERS<>1 AND ALLUSERS<>2, depending on how you intend to determine the ALLUSERS settings in your environment.