Before sending the envelope to the signer, the sender can set some fields, but how to hide the "custom files" tab, and how to hide the files under "standard", such as "Company"?
For "EnvelopeViews: createSender API" , the value of the QueryParameters can only be set as the default display value, all fields will still display.
If you want meta-data that is hidden from all recipients, you don't have to use a tab, you can use envelope custom fields. This add meta-data, but it's not visible on the envelope like a tab.
If you need only one recipient to see something that other recipients do not - you have to use document visibility. This is done at the document level only.