How do I import data into CRM subfields?

How do I import data into CRM subfields?

We have started using subfields to get around the lookup field limit on forms but we have not found a way to import data and populate them in bulk. On the backup and migration mapping they appear as separate file, like a separate module. But we can't find a way to populate them via import because you can only choose one file at a time when importing.

We tried to use the migration feature but we can't seem to populate the subform with contacts that already existing on Zoho. 

Is there a solution you can suggest to resolve this issue?


Thank you,

Joey