Trending @HCL; How to grow??

I joined HCL three years back as GET. I was working on a healthcare project . My domain was O365, Exchange online, giving support to end users regarding messaging flow and their office application. It's been three years and a few months now. I always wanted to move forward and change my domain. Can someone please advise how I should move in the same domain by upskilling? And what skill should I learn. I am clueless here. Because job opportunities are not so great in this domain. Also, I cannot see financial growth as well. Please share your advice for what I should learn and how I should grow myself?