Anyone ever come across splitting employee costs over different subsidiaries? With the interco JE's you can do things like rent and bills. But employee ones I;ve no idea

If you are using Time and Expense functionality (assuming) go to Financial > Create Intercompany Adjustments. It i9s specifically for Time and Expense. Also part of your ME close process

Long ago I had a similar scenario, employees from 11 subs worked on client projects cross subsidiaries. It was a nightmare during the month end. Came up with a complex scripted solution for labor cost rollup, 1st all the time entries were tallied up according to projects and subs. Then create inter company invoices and vendor bills from the time entries to allocate the cost between subsidiaries. Then also create customer invoices.