We see that the HCM connector has two options

1. Start Initial Sync

2. Block or hash sensitive data first

In both cases Fivetran extract data to the staging before the schema/tables showup. With the workday setup, we handle lot of sensitive data, users should be able to see the schema (tables and columns) first before Fivetran can start extracting the data. 

Given the HCM schema is predefined, let the Schema show up to the users immediately the connector is created, let the users select the columns they want and Fivetran run the extraction. If there are any tables or columns access is not there, Fivetran may throw a warning and ignore those tables and fields. 

Thanks

Leo H Antony