Shared Port DIA?

You know a DIA is both a "loop" and a "port" combination to get the total solution and solution cost.

Someone just asked me if SPs can offer let's say 3 loops at the cost of only the loop and then connect them all to a single "port". Effectively sharing a DIA port with multiple locations.

First of all, is this even a real thing? If it is, what's it called exactly and who offers it? The guy thought Cogent offered it but I cannot find a data sheet, etc about anything of the sort.

Thanks!