Reference:
https://docs.microsoft.com/en-us/azure/cognitive-services/luis/luis-concept-entity-types ML Entity with Structure An ML entity can be composed of smaller sub-entities, each of which can have its own properties. For example, Address could have the following structure:
Address: 4567 Main Street, NY, 98052, USA
Building Number: 4567
Street Name: Main Street
State: NY
Zip Code: 98052
Country: USA