Start a blog and start explaining things you’ve learned to the world.
This isn’t enough on its own, but reframing the knowledge you’ve gained in your own words is something that is worthy of practice, and will help you translate things in a work environment.
But here’s the key: pick someone you know who doesn’t have the same knowledge you do. Preferably someone smart but not technical.
Write for that person. As you write, try to imagine the questions they’d be forced to ask about the sentence / paragraph you just wrote. Is there additional context needed, or a useful abstraction to help explain the concept?
I gradually earned a reputation as an explainer after spending a lot of time blogging for my employer. I wasn’t good at it when I started. This really boils down to: empathy for the intended audience, and a willingness to write not for your fellow developers, but for those hoping to understand you and your fellow developers.
I transitioned into a PM role once I could translate things well. It’s challenging but rewarding. I don’t blog very often these days, but credit much of my current success to the things I learned by explaining hard things to a non technical audience.
Teaching and talks. You can do talks at local groups (or even conferences!). Even if you don't actually get to do the talk, writing the submission and preparing the talk help a lot.
Writing the talk lets you practice. Giving the talk lets you get feedback on how effective it was.
sounds like a skill issue