The useSelectedTermsOfSavedPost hook retrieves the ids of the selected terms of the provided taxonomy. It gets used internally by the useSelectedTerms hook which is a more full featured version of this hook.
import { useSelectedTermsOfSavedPost } from '@10up/block-components';
function BlockEdit(props) {
const { context } = props;
const { postId } = context;
const [
selectedCategoriesOfSavedPost,
hasResolvedSelectedCategoriesOfSavedPost
] = useSelectedTermsOfSavedPost('category', postId);
return (
...
);
}