How can i add a process that i have in another bpmn file into a call activity?
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Thanks 
Yes, the problem that i have is that if i import the second diagram, the one that should go into the call activity, using importXML the second diagram is visualized into the canvas but i don’t want that. Which function should i use to do this? Because for now i’m using a second instance of a modeler that is not connected to a canvas, to import the diagram and take the reference, but i don’t know if this way is correct
I think what you’re looking for is a partial import. There is currently no such feature.