Multi tenancy using Auth0 organization | Private & public

Hi there.
We develop a B2B multi tenancy application and we do authN using auth0.
We implemented it using Auth0 Organizations.

The issue that we have a customers that are private (no one should know that they are our customers) and public customer.

We don’t want that user will type his organization during login and then username + password.

We want that user will type organization + username + password at the same screen (if organization not exists there error will be wrongs creds or something).

There is some kind of solution for this?