Route to internal IP while on lan, otherwise, external ip

I have a couple services available to the exteal network. Im using apache virtual hosts to reverse proxy all my stuffs.

192.168.1.134 > site.domain.com

I want to redirect site.domain.com to its inteal ip, 192.168.1.134 when I am on the LAN.

This is helpful for things like plex. If i have a big download ruing, rather than streaming the content over the net and back to myself, if i coect to the inteal ip I dont need to worry about my bandwidth being utilized for the download rather than the stream.