In database view, you have the option to add "Business" (aka primary employment) information for a non-constituent on a relationship record. For example, if someone's spouse does not have their own record, you can add that spouse's employment information to the Relationship record, rather than having to create a separate record for the spouse and add it there.

In NXT, that information is viewable on non-constituent relationship records if it's added in database view, but there is no way to add it in NXT. It has to be added in database view, which will obviously be impossible once it sunsets.