InfoPath - How to check the duplicate row with multiple column in infopath repeating table.

I want to check the duplicate row with three columns(ProductID,ProductName,ProductCategory). So user should not enter duplicate row with the same ProductID,ProductName and ProductCategory(with these 3 combination). ex1:

ProductID    ProductName    ProductCategory
1            Aciloc150      Medicine

User should be restricted to enter the above same ProductID,ProductName and ProductCategory(1 Aciloc150 Medicine)

I know the below code using this I can check the duplicate value in one column, How can I check the duplicate row with the above combination(ProductID ProductName ProductCategory)?

count(/my:myFields/my:group1/my:group2[my:field2 != ""]) > 1 and (. = ../preceding-sibling::my:group2/my:field2 or . = ../following-sibling::my:group2/my:field2)

Here /my:myFields/my:group1/my:group2 -> repeating group xpath

My:field2 -> field in repeating table