could be a few things

for starters, you need to be on latest dashboard 17511, on a stealth server and have an unbanned console.

you also need dashlaunch 3.18.1

if your only looking to connect to neighborhood, then for starters i would set xbdm.xex on root of hdd, then set as plugin 1 on dashlaunch if your going to work offline enable liveblock/livestrong.

If you are going online and have your plugins set up for a stealth server then you will need to check with the stealth server if these should be enabled or disabled. most times they will need to be disabled if your using a stealth server.

once you successfully connect to the stealth server xbdm plugin should properly work and you should then be able to connect to neighborhood fine.

If you still have trouble connecting it could be that you need to

-allow media sharing on your PC.
-disable antivirus software
-turn off firewall

if your still having issues after that, i'd make sure your not using a vpn or something else that could be causing problems. people tend to have issues using vpns or hotspots

Are they on the same network or check setting of network in the dash launch