I guess you're more or less right. For example, maybe there's a university nearby with a bunch of talented, smart, educated business students, and you have a new project with a deadline that is going to be challenging to meet. You might say, "We would like to tap into that resource (i.e. the population of university students) to help us meet our production deadline". Meaning that you'd like to hire the university students over the summer, or something, to help produce your product. Or maybe your local community has gotten really interested in the environment lately, because everyone is worried about climate change, so you express your desire to "tap into that (resource)" to fuel interest in selling solar panels.