I think OP is looking for ‘clubs’.
Honestly I’d identify the top high schools - there’s several rankings on line - and ask.
Btw public hs may have clubs too or someone may start one. Most don’t have an aviation club, as an example, but my son started one. One could do the same with business - and at many schools probably have. I imagine this would have near zero correlation to getting into a b school or top school vs being in band, sport, having a job, walking dogs at the shelter. Not only do ECs not need to be major related, being well rounded likely helps - and pursuing passions will help as they’ll show in interviews and essays.
If you say a top b school - use Indiana as an example - where you go to hs won’t matter. Nor what you do.
That you meet the gpa and sat requirement for direct admit will be what matters.