Two position heirarchies for Purchase requisition document type ?

Hello,

We have a requirement where in we need 2 position heirarchies for the approval of purchase requisitions.

We set the position heirarchy 1 as default heirarchy for the document type, purchase requisition.

We want to route documents to heirarchy 2 using AME.

Now for heirarchy 2, what is the best place to store approval limits and cost centre information ?

For heirarchy 1, the approval limits and cost centre information is stored in Approval groups. Now the question is for heirarchy 2, where this details should be stored so that it can be maintained easily.

Thanks in advance,

Emma