Hi @Lissette Roman
The approach will depend on how the data is structured. Here are two examples:
1.One row per client, with each product in a separate column
To identify clients that have either Product D or Product E:
=IF(COUNTIF(F2:G2,"Yes")>0,"Exclude","Keep")
To identify clients that have both Product D and Product E:
=IF(COUNTIF(F2:G2,"Yes")=2,"Exclude","Keep")

2.One row per product

In F2, create a unique customer list:
=UNIQUE(B2:B1000)
Then, use the following formulas according to your requirement.
-Customers with both Product D and Product E
=AND(COUNTIFS($B$2:$B$1000,F2,$C$2:$C$1000,"D")>0,COUNTIFS($B$2:$B$1000,F2,$C$2:$C$1000,"E")>0)
-Customers with Product D or Product E
=OR(COUNTIFS($B$2:$B$1000,F2,$C$2:$C$1000,"D")>0,COUNTIFS($B$2:$B$1000,F2,$C$2:$C$1000,"E")>0)
-Customers with neither Product D nor Product E
=AND(COUNTIFS($B$2:$B$1000,F2,$C$2:$C$1000,"D")=0,COUNTIFS($B$2:$B$1000,F2,$C$2:$C$1000,"E")=0)

I hope this helps.