TL;DR: “Growing someone involves giving them tasks and challenges that push them just a little out of their comfort zone.” Very interesting article on Software Engineering ‘Management’
Some companies have an obvious career path. It’s worth talking to your team to see if their goals and the company path line up. If so that’s great and it’s easy for the both of you. If there isn’t an obvious fit, then either they will eventually leave or something will have to be created for them.