Don't worry, the chip you are searching is branded ExpressFabric and sold/made by Broadcom. It's AFAIK only PCIe4, and you get ones with up to iirc 96 lanes per chip. They support to be connected into a mesh, even adding shared PCIe devices like network cards, GPUs, NVMe and SAS/SATA HBAs is possible, though you might have difficulties with the GPUs in particular. The others, if you are careful when buying, should do well if they can handle SR-IOV, as (from their view), the mesh switch they are attached to is the root, and the computers attached to the mesh take the place a VM would normally occupy.

If you could get the smallest chip they make, it should not be hard to get a PCB made for it that fans out to e.g. a set of USB-C receptacles. One such receptacle can handle 2 PCIe3 lanes, and some power/USB-2 on the side. The main reason being the relatively low price, compared to e.g. mini SAS HD, which has a similar density and twice the lanes per connector, but also a slightly higher target impedance at the upper end of the PCIe spec, whereas USB-C is specifically targeting the perfect PCIe impedance.