Quick Qustion: How to find search fund accelerator (single sponsor) in the US

I'm currently searching for search fund accelerators in the US and wondering how to find them in the search fund map on this website. Is the best way to find them by filtering "single sponsor" and "company" in the map? When I filter them by just "single sponsor", a bunch of acquired companies supported by sponsors (search fund accelerators) also appear, which confuses me. It'd be great if you could help me find a better way to find a search fund accelerator on this website. Also, could you please elaborate a definition of "self sponsor"?