Just setup the share twice. One for your local subnet and another one for your VPN subnet.
"Well... lately this forum has become support for everything except omv" [...] "And is like someone is banning Google from their browsers"
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. Upload Logfile via WebGUI/CLI
#openmediavault on freenode IRC | German & English | GMT+1
Absolutely no Support via PM!
I host parts of the omv-extras.org Repository, the OpenMediaVault Live Demo and the pre-built PXE Images. If you want you can take part and help covering the costs by having a look at my profile page.