In what ways in The Time Machine do you see one group exploiting another group of individuals?
H.G. Wells uses the Time Traveller's trip to the far future as a platform to discuss social inequities that he sees at the end of the 19th century. The novel almost serves as a warning to people of what might happen if things continue on in the way they are. You can read more about the social injustice in the story on this eNotes page.
For instance, as the story progresses the Time Traveller comments on all the problems that could occur for humanity if certain members of society always have the best of everything: people will become complacent. He notes this obviously happens when the upper class is provided too much luxury. Unease also builds when there are other groups forced to work and live in unpleasant or inhumane conditions (the lower/working class).
When he arrives at his destination and is first introduced to the people in this far distant time, he notices that they seem to have very little concern for him and are much more interested in play and relaxation. It has become a world of stark extremes. The Time Traveller deduces that the Eloi must have evolved from the upper class, and thus have no struggles and no fear. All of the needs of the Eloi seem to be taken care of, and they have no means to produce or work themselves.
Later when he meets the ape-like creatures that inhabit the underground factories (The Morlocks) he realizes that the differences between those who live in luxury and those that don't are mirrored by the way in which the upper and lower class interact in his time.
There are some obviously severe social lines in this time period. The Time Traveller tries to make sense of it in his head and eventually we, as readers, realize that although the Eloi might have once been the dominant class ruling over the Morlocks, it is clear that the power between the two has shifted drastically. Now, the light-hating Morlocks exploit the Eloi's fear of the dark and utilize the peaceful people as a food source.