When you create a new Business View for an entity, this Business View allows you to display data to business users in the front-end application. 

In Business Views, you can add Transitions. A Transition allows you to add child entities and other objects so that you can provide more information to the business user.  

What's a Transition?

For example, if your Business View is for Customers, you could add a transition to the child entity Addresses. This transition will allow the business user to browse Customers and then see all the Addresses linked to that particular customer record.  

Other examples of child entities you can add including MasterRecords and GoldenHistoryRecords

Here is the documentation on how to add a new Business View and how to add Transitions.

Create New Business Entity vs. Use Existing Business Entity

When you add a new transition, the wizard that configures the child business entity of the transition will give you 2 options. You will choose between Create New Business Entity and Use Existing Business Entity.

Many xDM users are curious what is the difference between the two. 

Use Existing Business Entity

Use Existing Business Entity relies on the existing entity object. For example, if your root entity is Company and you add a transition to MasterRecords, the MasterRecords transition will reuse the same forms and collections for Company. 

It is hugely beneficial to reuse existing objects as it saves you time and avoids having to configure the new transition.

However, the downside of the Use Existing Business Entity option is, by its nature of reusing an existing object, you can't show a new form, collection, or have any other customizations when displaying the transition. 

Create New Business Entity

The Create New Business Entity option allows you to configure the transition differently from other entity objects. You can associate different Action Sets, Display Cards, Forms, and Collections to this transition. You can set different sorting behavior and many other options. 

For example, you may choose to use the Create New Business Entity option even if you're adding a transition to MasterRecords or GoldenHistoryRecords because it allows you to use a different Display Card and Collection. Imagine you have CustomerGolden collection view that contains the ID and cleansed Customer attributes, such as StandardizedCustomerName and GeocodedAddress. It has no attributes about the enriched values. In your CustomerMaster collection view, you could include other attributes like PublisherID, SourceID, PhoneticName, and   InputAddress values, in addition to the attributes in the CustomerGolden collection. 

The extra information is relevant in the MasterRecords view but could be too much to show in the golden view of the customer. The Create New Business Entity gives you the ability to tailor the user experience for the business users.

Which option should you use?

Carefully consider your business user's experience. In most cases, the option Create New Business Entity is the preferred best practice default. 

Why? Typically, the transitions benefit from different display properties. For example, MasterRecords and GoldenRecordsHistory should have different collections or forms compared to the view showing the Golden records.

Therefore, Create New Business Entity is the default option that designers should choose when they are unsure of which option to use.

The exception for the above rule is to use the option Use Existing Business Entity when you're certain you want the same collections, forms, transitions, etc. The most common example of when you should pick Use Existing Business Entity is the Ragged Hierarchy because it makes sense to repurpose the same display properties when you're displaying records from the same entity.