When you’re at work, be at work. Have a work mentality. How can you be the best employer/employee, manager/leader, etc. Have your mind on your work. Focus on the task at hand.
When you’re at the gym, be at the gym. Have a gym mentality. How can you get better today than you were yesterday? Have your mind on the sets, reps, technique, movement, breath work, etc. Focus on the workout.
When you’re at home, be at home. Have a family mentality. How can you be the best husband/wife, boyfriend/girlfriend, father/mother, brother/sister, pet-owner, friend, caretaker of the property, etc. Do you need to spend more time playing, reading, maintaining (the house), etc? Focus on being at home and leave the other stuff behind you.
Wherever your body is, make sure your mind is 100% there as well. Learn to compartmentalize your life. A “balanced” life is not being partially present in every aspect of life. It’s being fully present where you are and making sure you spend enough time with each aspect daily/weekly/monthly.