A.scala

package com.michal

class A {
  private def defaultPrivate = ???
  private [this] def superPrivate(other: A) {
    //other.superPrivate(this) // error
    other.defaultPrivate
    superPrivate(other)
  }
  private [michal] def publicInPackage = ???
}

B.scala

package com.michal

class B {
  def test(a: A) = {
    a.publicInPackage
  }
}

C.scala

package com

import com.michal.A

class C {
  def test(a: A) {
    // a.publicInPackage
  }
}