I'd say it's lower in the stack, and probably for a different audience. If you really wanted to, you can probably implement BeyondCorp using (but not only using

I'd say it's lower in the stack, and probably for a different audience. If you really wanted to, you can probably implement BeyondCorp using (but not only using) this or one of its competitors mentioned in this thread; but it's only part of the equation and leaves out the authorization logic of BeyondCorp.