Crossapp field allows the designer to form a one to one relationship between fields in two Microapps. The target field is identified using a search for a field value from another Microapp.
For example, Microapp A has the field Zone. Microapp B can reference the row in Microapp A using the Crossapp field and specifying the field Zone.
The target Buzz and Microapp must first be identified. Then the target Microapp field must be chosen.
Additional search fields in the target Microapp can also be specified to help narrow the search. More information can be found in the tutorial Microapp to Microapp Relationships.