One way to solve this would be to create an entity and set DG2 get data from database with the created entity.
When you call the microflow you populate the entity and choose commit and refresh in client. If you only want one object of this entity you could make sure to delete any old ones at the start of the microflow.
You could also use a list view for DG1 and let DG2 listen to the list with the built in functionality (listen to widget)