Access External HDD via WiFi (From a smart TV)

I have an external HHD attached to my iMac which is bassically packed with media files. How can I access that HDD through my Smart TV (or PS3). (I am using iMac as a media center, via wifi, using playback).

The HDD is simply not showing on the folders list (everything else shows up just fine i.e. Downloads, Machintosh HDD, so if a media file is in one of those folders i will find it and play it without any issues.

I know there is way to make the external HDD visible since I had the same issue 3-4 years ago and I managed to find the answer BUT i dont know where 😟