Different Company Codes

Dear All,

I have to implement SAP HCM for 6 different Company Codes. The difference between them is only with regard to their Enterprise structure and rest Personnel and Pay scale structure is same. Employees are obviously different in all company codes.

1. How will I achieve this?

2. How will I segregate employees and different behaviour of Wage types basis on employee groups and sub-groups?

3. How will I tell system that my MN01 allowance grouping is for Co Code 1000 and AL01 is for Co Code 2000?

Please suggest

Thanks,

Megha