import { type MultipleSelectBoxOption, type AllowedValueTypes } from '../MultipleSelectBox.types';
/**
 * Flattens options with only one level of nesting.
 * only one level of nesting is allowed.
 * Group labels are preserved, followed by their immediate children.
 *
 * @param options - The options array to flatten
 *
 * @returns Flat array of options, including group labels and their children in order
 */
export declare function flattenOptions<T extends AllowedValueTypes = string, AdditionalProps extends Record<string, unknown> = Record<string, never>>(options: MultipleSelectBoxOption<T, AdditionalProps>[]): MultipleSelectBoxOption<T, AdditionalProps>[];