src/vs/platform/list/browser/listService.ts/getDefaultTreeFindMode
function getDefaultTreeFindMode(configurationService: IConfigurationService) {
	const value = configurationService.getValue<'highlight' | 'filter'>(defaultFindModeSettingKey);

	if (value === 'highlight') {
		return TreeFindMode.Highlight;
	} else if (value === 'filter') {
		return TreeFindMode.Filter;
	}

	const deprecatedValue = configurationService.getValue<'simple' | 'highlight' | 'filter'>(keyboardNavigationSettingKey);

	if (deprecatedValue === 'simple' || deprecatedValue === 'highlight') {
		return TreeFindMode.Highlight;
	} else if (deprecatedValue === 'filter') {
		return TreeFindMode.Filter;
	}

	return undefined;
}