Having this example sheet (just sample data)
Column-A Column-B Column-C
1 claudia claudia@gmail.com SOLD
2 claudia claudia@gmail.com CONTACTED
3 natalia natalia@gmail.com CONTACTED
How to use FILTER to filter row 3, that is to say: rows where colum-c is CONTACTED but excluding duplicated rows where one of the duplicated instances has "SOLD" within column-c.
Definition of "duplicate": same email (column-b)
try like this:
=FILTER(A1:C, C1:C="contacted",
NOT(REGEXMATCH(B1:B, TEXTJOIN("|", 1, FILTER(B1:B, C1:C="sold")))))