This behaviour is called copraphagia and most mammals have some individuals that display it. Meat eating mammals tend to seek out and eat vegetarian mammal poop but are not adverse to their own or other carnivore poop. It can become an obsession with individuals and once the pattern is set it can be a very difficult habit to break.
With dogs it is likely that observing the dam cleaning up after pups is the trigger to this behaviour - but not always...
If it is a behaviour copied from the mother then you must not allow any dog to toilet without observing them - then pick up as soon as possible.
If the dog is eating only its own and other pack members poop then it is worth considering what type of food you are giving them. Pet food is often just too overloaded and the animals can't digest all the goodness, or more likely, the taste of the food. The poop still smells like it is worth eating. Change brand to something that has less protein, the most famous or most expensive is not always the best, add bran or cooked greens and stop giving treats. If you like giving food rewards to your dogs try tiny bits of carrot instead of stuff bought in packets.
More than anything break the habit - it is a bit like smoking - don't allow access to free poop for several months, along with diet changes and you should see a difference. Good luck!