How to specify the mount points for multiple lower layers?

[Alkis Georgopoulos <alkisg@gmail.com>]

 From https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt:
mount -t overlay overlay -olowerdir=/lower1:/lower2:/lower3 /merged

How can I specify that I want e.g. lower2 to be mounted at merged/home?

If all lower* layers can only be mounted at /merged, then I don't see 
any way at all that overlayfs would allow me to combine e.g.
Partition  MountDir  MergedDir
------------------------------
/dev/sda1  /root-fs  /merged
/dev/sda2  /home-fs  /merged/home

I even tried to create a fake directory structure like this:
/dev/sda2 /fakedir/home /merged
...so that I would mount /dev/sda2 to /fakedir/home, and then try to use 
lower2=/fakedir, but then I got a different issue, that overlayfs 
doesn't include submounts, so sda2 wasn't visible at all then.

So I was unable to combine the root and home partitions to the correct 
paths using overlayfs (I'm planning to use a tmpfs as the upper dir 
later on).

Any help? Thank you!