Boo Radley, Mayella Ewell, and Dolphus Raymond all hide their true selves in order to be accepted. For Boo, however, the desire for "acceptance" by the larger community is very minimal - he is a shy, reclusive man who no longer knows how to socially interact with the outside world, nor does he desire to do so - except when it comes to Jem and Scout.
With Jem and Scout, Boo seems to feel a desire for friendship. The reclusive Boo reaches out to the children through the gifts he gives them, the blanket he puts on Scout, and the mending of Jem's pants. He keeps himself from view, but he gets over his agoraphobia enough to exit his house to do these things. His brother tries to prevent this contact by cementing over the tree hole where Boo leaves the presents for the children, but this same tree is the place where ultimately they connect in the most significant way possible, for it is here he comes out of his house to save their lives.
Boo is more than accepted by Jem and Scout. As Scout stands on his porch at the end of the book, she at first feels a bit guilty that he gave them so much and they gave nothing in return. However, she soon realizes they gave him vicarious life experiences:
Summertime, and his children played in the front yard with their friend.... Fall, and his children trotted to and fro around the corner.... Winter, and his children shivered at the front gate, silhouetted against a blazing house.... Summer and he watched his children's heart break. Autumn again, and Boo's children needed him (148).
Mayella hides her true self - a lonely white woman who is abused by her father and who has fallen in love with Tom Robinson - in order to be accepted by Maycomb society and to avoid another beating from her father. She cannot admit to her feelings for Tom because it is not acceptable for a white woman to love a black man. What's even worse, Tom did not reciprocate her feelings, and now she is just left with feelings of guilt and shame. Her only recourse for acceptance is to accuse Tom of a crime and be rid of him from her life. As Atticus points out in his closing remarks:
"She must destroy the evidence of her offense. What was the evidence of her offense? Tom Robinson, a human being. She must put Tom Robinson away from her. Tom Robinson was her daily reminder of what she did. What did she do? She tempted a Negro. She was white, and she tempted a Negro. She did something that in our society is unspeakable: she kissed a black man" (109-110).
She hopes for acceptance, but while she gets the verdict she hopes for at the trial, the majority of Maycomb saw right through her testimony. She gains no higher status and only comes out more pathetic.
Dolphus Raymond also hides his true self - a white man who loves a black woman and has "mixed children" with her - because such a relationship is not accepted by society. He hides behind a paper bag pretending to be a drunk, when really, he is only drinking coca cola. He explains to Scout and Dill why he does it:
"Some folks don’t—like the way I live.... It helps folks if they can latch onto a reason. When I come to town ... if I weave a little and drink out of this sack, folks can say Dolphus Raymond’s in the clutches of whiskey—that’s why he won’t change his ways. He can’t help himself" (107).
By pretending to be someone he's not, Dolphus Raymond gains a kind of acceptance he would not have otherwise.