Apologies if this has already been asked, but I keep looking and think I may be over - complicating things.
If possible I need to find a way to find which week a person appears and what session they will be taking (see attached file), I have worked out how to find out which weeks a person is taking with - =IF(AND($A$3:$A$23=$A3,$D$3:$D$23=I2),$F$3:$F$23,"") but I need to break it down to the group as well. So I need to be able to say x person is taking x activity with x group in x week.
Any help would be great, please feel free to tell me I am over thinking this.
I suspect I don't fully understand what you're trying to do here, but looking at the data and seeing what you've written, I do wonder if the Pivot Table capability would give you the result you want, rather than an exotic formula. The Pivot Table offers ways to take a database such as you have and summarize it in rows and columns with counts or sums in the intersections. Take a look at the attached to see if the method works--I may be totally off base, and this may not have the rows and columns you would want, but that's easily changed.