Chaining OpenVPN servers (Two Merlin-N66U)?

[loveleeyoungae]

Hi,

I currently have the following setup:

(A) At my Parents', I have a N66U running as an OpenVPN Server and a Foscam camera.

(B) At my Home, I have another N66U running as a client to connect to the remote Parents site.

Devices on BOTH sites can access one another.

I've also managed to set my Home N66U run as an OpenVPN Server at the same time so that I can use my iPhone/iPad to connect remotely to Home while I'm on the go (C).

Now my question is:
Is it possible to let the OTG iPhone (connecting remotely to Home) access the Parents' devices (specifically the Foscam)? Steps, commands...?

Thanks in advance.