This post was prompted by a fellow having issues with his Homegroup settings in Windows 8. I hope it helps you overcome your issues too.
After successful setup and joining of you Homegroup on all clients on your network, confirm you can see other clients in the Homegroup, open a few of them and see their shared files. You can use DLNA-aware Media players in the Store, like sMedio TrueLink+ to stream media shared by your Network Clients.
Still Can’t See Others?
If you still can’t see other clients, check to see that your Network has been setup as Home Network as follows:
Do this on all Clients that should participate on your Homegroup, after this you should now see all other clients and what they are sharing. Remember, you DON’T need to turn Off Firewall, and you should never turnoff you firewall. If Bill Gates comes with a million bucks and asks me to Turn Off my firewall I will not do it. My principle is, if it doesn’t work with my Firewall turned ON, I am not going to use it. Homegroup works through Firewalls in both Windows 7 and Windows 8, if you are having Homegroup issues on any of your clients, run the Homegroup Troubleshooter instead of turning of your firewall.
All the best with your hunt.