Thanks. I guess I'll have to fill in the blanks. Wouldn't know how to
create a macro like that.

When you fill in the blanks, you could include conditional formatting
that would hide the display (make the print color the same color as the
background, eg white on white), depending on the relationship of the
"blank" cell to the cell above. So the "blanks" would still appear
blank.

How big is this list (how onerous will it be to "fill in the blanks")?

What do the actual contents of the first few groups look like (to give
an idea of what you could use to "fill in the blanks" and what the
conditional formatting would have to look like)?

If a group relating to A1 is B1,B2,B3,B4, do the cells in B1:B4 have to
stay in order after the sort, or do they simply have to stay with the
contents of A1:A4?