I see, so it is normal that my dog loses his concentration when performing outside i thought that she dislikes doing tricks in front of others or she don't like to be commanded in front of others.
I'm not sure how (or where) you train your dog - but have you ever noticed that, let's say for example, you teach your dog to "SIT" in the kitchen, and whenever you're in the kitchen and ask your dog to "SIT", she will, and she'll do it every time, but then you go into the living room, and ask her, and she just looks at you funny, like she has no idea what you're talking about? It's because dogs don't generalize things the way we do. You have to basically teach them that SIT means the same thing in the living room that it does in the kitchen. So - you have a few training sessions
in the living room, and presto, she SITS in the living room, too. Then - you move into a bedroom. Start over - but this time, you may only have to ask once or twice - and bingo, she's doing it perfectly. NOW, you've got to move outside - and you may have to start all over again. Not only is she in a new place, but now there's new distractions - birds, noises, smells, all kinds of stuff that she's thinking about, all the while, she's trying
so hard to remember what SIT means. So - you go over and over it
outside -- until she does it perfectly. And this goes for all her lessons. She needs to learn them in a whole lot of different contexts - different rooms, inside/outside - and then with different people present. Some dogs get very excited or nervous in front of lots of people, and may "forget" how to do things.
I'm not sure what tricks your dog knows, but if she won't do them in front of people, maybe you could start training all over again, just you and her, go slowly with her, give her really good rewards for doing them, be very patient with her, give her loads of praise, let her know she's doing a good job for you - and once she's doing the tricks the way you like in one room, then the next day, try a different room - and start all over again. Practice, practice, practice - then go outside. And start all over again. When that's going really well -
then see if she can do them in front of ONE friend. Don't put a lot of pressure on her. If she does well, reward her and tell her what a GOOD GIRL she is!!! It will really help her confidence. If you've shouted at her previously, she might be afraid of disappointing you and getting yelled at again, so right now she may be afraid to perform. Start really slowly, with things you know that she knows. Set her up for success, pay her well, give her really good treats - and she'll come through for you, just you watch!