Abc 500
abc -500
bbb 300
bbb 250
cac 100
cac -100
ddd 200
ddd 300
fff -500

I want to be able to highlight data in column B where amount is identical (ignore negative sign) only where data in column A is identical.

In this particular case it should highlight 500,-500 where data in column A = ABC & also 100,-100 where data in column A =CAC.