Find duplicates for each parent using VBA in Excel

Have to columns Column 1 and 2
For each value in Column 1 , will have multiple values in column 2.
Need to find our duplicates in Column 2 for each value in column 1.

Child values can be repeated for different parent values. But under each parent there should not be duplicate child values.
Need a VBA code to handle this.

Attached the sample excel, with expected output column.