Using plays or other works written in dramatic form can present a challenge when analyzing narrative point of view. If you are not looking at narrative point of view, however, and instead are looking at social perspectives offered through works of literature, plays can work as well as anything else.
In yet another possibility, you might be looking at social commentary instead of social perspectives, assessing what each work has to say about the world as opposed to what social group or identity is being used as the focus of the work or being expressed through the work.
I don't see many similarities between these two works. One of them, Night, is a personal account of one man's journey during the Holocaust. The other, A Raisin in the Sun, is a play about many people's journey of lost hope and dreams. Perhaps there are similar themes (oppression, loss of hope) in these two literary works, but their points of view do not seem to be very similar.
Others might hold different opinions, but I think both works are told from different points of view. Part of this might be due to the different genres each represent. In Hansberry's work, the development of drama is something that we understand from different characters through dialogue, stage directions, as well as through background information that comes out at different points in the drama. There is not a specific character that drives the telling of the action. It is in this point where Wiesel's work differs. In Night, the point of view is Eliezer's. He owns it and the reader understands what happens through this particular frame of reference. Rarely, if ever, is this point of view absent. Eliezer's eyes are the means through which we comprehend the horror and terror of the Holocaust. In this, there is a difference between both works.