Can I use environment variables in the "config.in" of buildroot?

Question

I wonder if I can access environment variables (or argument passed when running make) in buildroot .in files. For example, I like to have a Config.in file like this:

config BR2_PACKAGE_MY_PACKAGE
        bool "my_package"
        select BR2_PACKAGE_XYZ if $(NEED_XYZ) = "y"
        select BR2_PACKAGE_GTEST
        help
          This is my package.

where NEED_XYZ is an environment variable (or make variable). Can I have such configuration file? If no, what do you suggest to achieve similar behavior?