Join an existing Party

If you can call it a dashboard. Honestly I wish there was a way to change it so it would look like the old 360 format, this Windows 8 formatting has to go.

As Scratch says, it seems to vary from game to game. For Battlefield 4, you need to start a party and invite friends. If they're also in Battlefield 4 (in which case it becomes a Battlefield 4 party), when you join a game, it'll bring your party with you.
If party members are in existing games/lobbies, a pop-up notifies you that the party leader/member is joining a match and gives you an option to join with them.

Hi

If you only want to only talk to friend you need to join an existing friends part or start a party and invite your friends to that party as per the guide below.

support.xbox.com/.../how-to-start-a-party

I'm also having an issue with the party chat functionality. My system will let me join a party but I cannot hear my party talking nor can the other members of the party hear me. I've tried doing the factory reset multiple times and have updated my controllers
yet the problem still exist. It doesn't matter if I use my headset or try to use the kinect. Nothing can be heard by either party. Please let me know what I have to do to rectify this situation.

If you joined a Party in console you will need to leave that party firs before joining a party in the app.