So, when I say:
<Button
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_marginLeft="@dimen/login_left"
android:layout_marginTop="@dimen/login_top"
android:text=""
android:id="@+id/button_login_fun" />
And I state in dimens.xml for screen size 1080x1920 and density xxhdpi:
<dimen name="login_left">325dp</dimen>
<dimen name="login_top">140dp</dimen>
I receive a different button position for Nexus 5 and Nexus 5X in Preview in Android Studio: Nexus 5