[JuneBug]

Welcome to RAV4World! I don't remember anyone on this forum repairing this particular seat belt. Most of us rarely use the thing. You may be able to find something here:

share.qclt.com - /丰田Toyota RAV4 Repair Manual/

Edit: I think this is what you're looking for:

http://share.qclt.com/丰田Toyota RAV4...r Center Seat Outer Belt Assembly/0440012.pdf