Presenting a new work in different seminars in the same department I work in mathematics and sometimes my work is on the border of two different subjects: analysis (my main specialization) and geometry. In my department there are both analysis seminar and geometry seminar. 

Is it common to present the same new work in both seminars if I believe that the work might represent some interest to both groups?

If it matters, I am working in an American university and I am relatively new in this country.
You present your work to colleagues, not a formal group under a certain name. If you think there are people on both seminar groups who are genuinely interested in what you do and with whom you would like to collaborate in future - there is nothing wrong in presenting your results in both seminars. 

However, there is no point (and no joy) in presenting to a wrong audience, or, in other words, in presenting a wrong talk to a given audience. If you decide to present in two different seminar groups, focused on different topics, make sure you rework your presentation accordingly. In fact, you have to present two different lectures,  each adapted to interests of a particular group.