import { UASLocalMetadataSet, SecurityLocalMetadataSet } from "webklv";
import "webklv/misb/misb0102"; // register the nested parser

const outer = new UASLocalMetadataSet(valueBytes);

// Access the nested security set (Tag 48, key 0x30)
const security = outer.get(SecurityLocalMetadataSet.key);
if (security instanceof SecurityLocalMetadataSet) {
  console.log(`${security.items.size} security items parsed`);
}