How to split a one contractor expense made to multiple contractors?

@bchamble-p5datasolutions  Dunno that I'm following your question here.

If you're paying multiple contractors with multiple checks, then you do so. At year end, issue 1099-NECs as appropriate.

If you're paying one contractor and they have several subcontractors that they divvy out payment to, then there is no explicit reason to split them apart. They will issue 1099-NECs to their subcontractors, not you. You'll only send one to the main contractor.