How to display complex objects in multipart/form-data requests in Swagger UI?

I am using OpenAPI 3.0.1 and I am trying to send a request as multipart/form-data. The request body is defined as follows:

       requestBody:
         content:
           multipart/form-data: # Media type
             schema:            # Request payload
               type: object
               properties:      # Request parts
                 media:            # Part 1 (string value)
                   type: string
                 address:       # Part2 (object)
                   type: object
                   properties:
                     street:
                       type: string
                     city:
                       type: string
                 profileImage:  # Part 3 (an image)
                   type: string
                   format: binary

Here, the address field is an object. Swagger UI shows the address field itself, but does not show its properties street, city. Why is that?