Combining a variety of data from different columns

Welcome to the forum.

Assuming that your 'online' Excel is 365 (please update your forum profile accordingly), try this to generate lists:

=LET(u,TRANSPOSE(UNIQUE(SORT(TOCOL(B2:H4,1)))),n,IFERROR(DROP(REDUCE("",u,LAMBDA(z,y,HSTACK(z,FILTER(A2:A4,BYROW(B2:H4,LAMBDA(r,COUNTIF(r,y)))=1)))),,1),""),VSTACK(u,n))

Pulling these apart into different sheets automatically would require VBA, which is NOT supported in the online version. It can be done if you pre-create the subject sheets like this (see attached):

=LET(d,Master!L2#,f,FILTER(DROP(d,1),TAKE(d,1)=A1),FILTER(f,f<>""))

or

=FILTER(Master!A2:A4,BYROW(Master!B2:H4,LAMBDA(r,COUNTIF(r,A1)))=1)

So you still haven't replied here or marked the thread as solved, despite telling me that you have!

It's extremely discourteous NOT even to acknowledge help given, however small that assistance might have been. On this occasion, I gave you an awful lot.

The rep is very kind - thanks. But you added that today.

In January, I gave you this assistance. That's three months ago. Not ONE word from you back then of recognition, not even a 'thank you'. That's what I find discourteous - it feels pretty much like a smash and grab.

Please remember that we are all human beings - treat us with the respect that we deserve, please.

You still need to mark this thread as solved.

OK - so I have marked this as solved on your behalf.