It is best not to use "Field A, Field B" references, or Table 1, Table 2, etc. Use real field names.
None of your fields are labeled. It is impossible to tell what you are talking about, it is impossible to know which is A or B.
Searching with operator ! in Field B will find all duplicate records (only). Then you just sort your records on Field A
Thank you- sounds pretty easy. Wasn't familiar with the ! parameter.