I'll give an example to explain what I'm trying to do.  If I have employee x and I have 2 separate tables which schedules employees for a specific day, lets say 6 March 2023.  Is there a way to ensure employee x is not selectable as an employee in table 2 if they are scheduled in table 1 for 6 March 2023 already.  

I already have 4 tables separating 4 different sets of instructors, which links to my schedules for my teams of students going through training.  At any given time I have 8 teams of students which all overlap each other on the same day.  So to make life easy for scheduling purposes, I want to ensure if employee x is scheduled on lets say Team 1, can I ensure employee x is not selectable on Team 2 schedule.  I hope I explained this well, and thank you for your time.