adb push Dir /sdcard/Dir/Subdir

Permission denied

ls -l

drwxrwx--x root sdcard_rw

cd /sdcard/Dir/Subdir
mkdir XYZ

mdkdir: XYZ: Permission Denied

su
mkdir XYZ

adb push XYZ /sdcard/Dir

# ls -l on /data/media/0/Dir
dwrxrwxr-x root root

/sdcard/

cd /sdcard/Android/obb/app.example.test/
cp /sdcard/test.obb .
ls -la