First off, in real-time (not history mode) the "Top Connections" by Network/CPU screens of cpview will not be populated by default unless you enable them as specified in the following SK, can you currently see Top Connections in real time? sk167903: CPview Top Connections and Protocols tabs show no data If you can't see them in real time they won't be recorded for history mode.
Another related historical method you would be able to use is running fw ctl multik print_heavy_conn which will show you all identified elephant flows over the last 24 hours.
Also be aware there is a relatively new tool called top_conns that can also show top connections by CPU usage in real-time: sk172229: Top Connections Tool
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