Duplicates Highlight with condition from second column

[akampianakis]

Hello world,
so I have the sheet as seen in the attachment (I have included a picture)
I have 2 columns, A for machines, B for products. I want to highlight those products that are created from both machines , so something like if duplicate and column A in the range of the duplicates contains both A1 and A2, highlight the range/cell, or something that identifies that.
Is that possible?
Thanks!

 

[etaf]

Ignore - Not quite write , that was duplicates and not for A1 or B1
i'll think

 

[etaf]

=COUNTIFS($A$2:$A$100,"A1",$B$2:$B$100,$B2)+COUNTIFS($A$2:$A$100,"A2",$B$2:$B$100,$B2)>1

for 2007, 2010 , 2013 , 2016 , 2019 or 365 Subscription excel version
Conditional Formatting

Highlight applicable range >>
A2:B100 - Change, reduce or extend the rows to meet your data range of rows

Home Tab >> Styles >> Conditional Formatting
New Rule >> Use a formula to determine which cells to format
Edit the Rule Description: Format values where this formula is true:
=COUNTIFS($A$2:$A$100,"A1",$B$2:$B$100,$B2)+COUNTIFS($A$2:$A$100,"A2",$B$2:$B$100,$B2)>1

Format [Number, Font, Border, Fill]
choose the format you would like to apply when the condition is true
OK >> OK

Book1
	A	B
2	a1	fred
3	a1	john
4	a1	jill
5	a1	gill
6	a2	jill
7	a2	sally
8	a2	fred
Sheet1

Cells with Conditional Formatting
Cell	Condition		Cell Format	Stop If True
A2:B8	Expression	=COUNTIFS($A$2:$A$8,"A1",$B$2:$B$8,$B2)+COUNTIFS($A$2:$A$8,"A2",$B$2:$B$8,$B2)>1	text	NO