Damir, the debugger uses the XSLT transformation SJSON2HTML to visualize JSON. Try it out: When you pass a JSON data object in its SAP-internal XML representation ( with <object>'s, <array>'s, <str>'s and so on), this transformation creates HTML code which visualizes it. You can use this transformation, and then pass the created HTML code to an HTML control.
Regards,
Rüdiger