I hope you mean another schema to create objects for storing data. If so, then I don't think that is allowed. You may want to check with your SAP account manager on the specific details on your licencing. But it is now allowed to have "Non BW managed" persistence on SAP HANA Platform edition.

Although, you can reconfirm with SAP account manager, if you can create a DDIC table object in the BW schema.

Any specific reason why you want to create another schema. There could be alternatives within the current licensing agreements.