Lots of us seem to know our general area of expertise. We are engineers, accountants, sales people, copy writers, attorneys and other professional types.
Knowing your "supporting professional focus" can be very useful in identifying and obtaining the best position for yourself, and it is easily accomplished.
Look back in your professional and personal endeavors and think about the "role" you played on an engineering team, as a member of a corporate accountingteam, as a member of a successful sales organization. Recall what "role" you typically played or were asked to play by others.
Did you organize the meetings, set the strategy, take the notes, run the budget numbers, come up with the creative solutions, write the policies and procedures or lead the entire effort? As a subject expert, what is your "supporting expertise".
It is that dual role that you should reflect in your resume's "Objective" statement. "Highly-experienced corporate software developer at leading US and International Software Firms with unique ability to create profitable products based upon accurate cost projections and efficient product development procedures".
Now, the reader will know that you are 1) a seasoned software developer who can 2) work effectively with the finance, marketing as well as the R&D professionals to successfully launch profitable software packages. If that is what they are seeking, you have made it clear that you are a potential candidate. If it is not what they are seeking, then you very likely do not want the job as it is not "in your wheelhouse".
Take a look at your resume and your biography and ensure that you have this key information in a prominent position. Also, it should be on your LinkedIn profile and at other locations where you are marketing yourself.