How do you enable “Deep Work” in an open environment where you are playing the role of a manager, whose key job is to enable the team reach their full potential.

I block my calendar for important items where I need time to focus. As long as my calendar shows free expectation is set for members to freely approach me for anything they need help or guidance on. This is on top of scheduled one on one seasions with them to check how they are doing and get feedback on how I can support their growth.

This is actually a very good and hard question to answer. I find that it has to be integrated in at bookends of the day to be done consistently. This is something I really struggle with and tend to do best in the morning. Also there are certain project's which get help from those who I manage who i can encourage deep work with or to do independently and share how went.

You are leader of the team you have to show habit of deep work in your behavior then your words will be backed by your actions and everyone in your team will follow that

Pick a point where you need to focus on a particular task (such as answering emails or writing reports) and use that as your deep work.

The short answer is, you don’t. Pick another task. Tasks that require unpredictable reactions like managing don’t follow the deep work format. But, that said, there will be some tasks in your work that require engaging on the same topic for 25+ minutes. Writing a series of emails, reviewing evaluation reports, or writing a proposal. Use deep work for tasks like that.

in that situation i would focus solely on the idea of supporting your team for 25 minutes. ignore all other responsibilities.

You should be able to follow the same guidelines. Eliminate distractions and pick a goal/task to accomplish. If everything on your list is small tasks, then go through those one at a time until your deep work session is over. If the task is talking with or listening to your team, then giving them your complete attention is still a form of deep work.