"KL" wrote...
try something like this:

if there are no empty cells in column B, then

=SUMPRODUCT(--(FREQUENCY(MATCH(B1:B5,B1:B5,0),
MATCH(B1:B5,B1:B5,0)*(A1:A5="Jan")*(C1:C5=2))0 ))
....

Even using the OP's data,

Month Branch Item
Jan A 1
Jan B 2
Feb C 1
Feb C 2
Feb A 1

your wonderful formula returns 2 even though only the second row
matches the (A1:A5="Jan")*(C1:C5=2) criteria. Can you figure out why?
Did you bother to test? Rhetorical - obviously not.