Hi Ekta,
What you are requesting is not possible currently through FDM.
You could instead achieve consistent masking, that is, you can create your maps such that if name X gets masked to Y in the customer table, the same name X will get masked to Y also in the purchase table. This can be done using a HASH function, for example HASHLOV, or cross-referencing.
If you still wish to pursue your original requirement, you will need to submit an enhancement request. To do so, please post an 'Idea' on the TDM Community page here:
(Content -> (Actions) -> Create an Idea)
Please also include the business need for this enhancement, how soon you would need it, and the potential business impact if it is not provided.
You and other community users will be able to 'vote' for this enhancement request. It will be reviewed by product managers at frequent intervals who will decide if the enhancement will be added to the product and when. You will be notified of the enhancement request's progress by the Idea post being marked as 'Under Review', 'Currently Planned' , or 'Delivered' by CA.
Thanks,
Sameer