I had the same issue with such a complex xml file which had nested scrollview. I fixed the issue by dividing xml file into another layouts and include them in one file by referring.
Let's say you have a main_layout.xml file which you are working on it. Create another xml files by taking out the appropriate sections. Example,
main_layout.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:id="@+id/lytFirstContent"
android:layout_alignParentTop="true"
android:layout_height="wrap_content">
<include layout="@layout/first_content"/>
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:id="@+id/lytSecondContent"
android:layout_below="@+id/lytFirstContent"
android:layout_height="wrap_content">
<include layout="@layout/second_content"/>
</RelativeLayout>
</RelativeLayout>
first_content.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_alignParentTop="true"
android:layout_height="wrap_content">
<!-- Your other views -->
</RelativeLayout>
</RelativeLayout>
second_content.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_alignParentTop="true"
android:layout_height="wrap_content">
<!-- Your other views -->
</RelativeLayout>
</RelativeLayout>