A Call Service node is used to call an existing flow in the UI Services editor.
Service: Choose the service from which you want to call the flow.
Flow: Choose the flow you want to call.
Input/Output properties: Based on the service that you select, the Call Service node displays all the properties that you would have created in the called service and auto-fills the Key field. In the Value field, you can select the following property type and then enter the property name.
bh.: The global object which contains input, system, and local properties.
bh.input.: The property which contains only input variables.
bh.local.: The property which contains only local variables.