Like many people, I’m not a one-trick pony. I have many talents, and I try to bring them all to bear on problems that I am asked to tackle on the job. The ability to house multiple skills in single individuals is an efficiency for every organization. Many a supervisor, including me, has expressed appreciation to an employee who takes on challenges outside their assigned or expected scope.
However, when employers hire, they seldom look for diversified skills in a single individual. Hiring is generally a process of pigeon-holing candidates in one discreet role or another. I have found this over and over in my career. I do a lot of things pretty well, but people want to hire one thing. When you job search you want to be focused on selling that one thing. Once you get the job, you can let yourself be many things again.
This doesn’t mean your entire job search needs to be focused on a single skill. To the contrary I recommend pursuing multiple job-function prospects simultaneously, just not with the same potential employer. Make sure the resumes, cover letters, and interviews focus on the job being offered, and not your entire skill set. At the hiring stage, it’s not about showing off everything you can do (that comes after you’re on the job); it’s about showing them how well you can do the specific things they are seeking now.