Short answer: ‘Level-1 is your friend’
Show at least level-1, the top-level structure of the implementation.
As detailed as your stakeholders need it. In many cases, refining just a few of the top-level building blocks will be sufficient - with safety-critical system (as always) being an exception!
When development teams have a clear understanding of important crosscutting concepts (arc42 section 8), they sometimes don’t need a detailed building block view.