Exporting routes from one protocol to another and from that protocol to the first one are discrete configuration functions.
For example, to run OSPFv3 and RIPng simultaneously, you must first configure both protocols and then verify the independent operation of each. Then you can configure the routes to export from OSPFv3 to RIPng and the routes to export from RIPng to OSPFv3. Likewise, for any other combinations of protocols, you must separately configure each to export routes to the other.