Highlight all numbers in column B with duplicates that are in column A?

I use old Excel 2007 and have two columns. Column A contains 250 unique values. Column B contains 1000 values where some are duplicates.

If a value in column A is in column B, I want to highlight/color the value in column B.

I have tested conditional formatting and searched for duplicates but since column B contains duplicates, they are also selected even though they are not in column A. I can't use a formula if A1 = B1 and so on because the same value is probably not on the same row.

Example table

A      B
111    323
2222   111
333    111
444    2222
       777
       888
       888

I want to highlight 111 and 2222 in column B above.

Solution 1:

Using a conditional formatting with a COUNTIF formula like in the screen cap below might be what you are looking for. (COUNTIF(A:A,B1)

If not hopefully it gives you some ideas.