Filter data from different buckets


I have bucketA where _value contain strings
I want to create a new label with map in bucketB when bucketA _value match with bucketB value
or just simply filter out from bucketB which are exists in bucketA

join is not an option as at the end i need to list those items from bucketB which are NOT in bucketA
so is this possible if yes what would be the best approach


Discovering and understanding the new join package was helped to solved this problem

btw InfluxData you should update the gui script editor as its offer old join with methods other than inner but they are not supported