Displaying the last value corresponding to the last occurrence of a combination

Hi all!!

So I have two Columns (B and C) which combined make 1 name and have a value associated to them (which changes every time the combination occurs).

I need to check what was the previous value for the combination so I can see whether the newer occurrence was higher or lower.

I think I got part of the problem, as you can see in the attachment, but I need it to display just the previous one, and not keep on adding.

ExampleOccurances.xlsx

By the way, the table is much bigger than this and will continually grow.

Thanks so much.