How to display subcategory and its child items in facet

we can display subcategory and its child items in facet, it is three-layer view of facet category.

	plp.addToViewContextDefinition('Facets.FacetedNavigationItemCategory.View','displayValues', 'array', function (context) {
	var categoryinfo = plp.getCategoryInfo();
        var categoriesConfig = Configuration.categories

 	var sideMenuSort = categoriesConfig.sideMenu.sortBy;
	var additionalFieldsSide = categoriesConfig.sideMenu.additionalFields

	var flagSide = _.contains(additionalFieldsSide, sideMenuSort);
	if (!flagSide)
        	categoriesConfig.sideMenu.additionalFields.push(sideMenuSort)
		var siblings = categoryinfo.siblings ? categoryinfo.siblings.length : 0;
		var sequencenumber = parseInt(categoryinfo.sequencenumber);
		var currentCategory = {
			displayName: categoryinfo.name,
			isActive: true,
			label: categoryinfo.name,
			link: categoryinfo.fullurl,
			subCategory: (categoryinfo.categories) || [],
				additionalFields: {
				metakeywords: categoryinfo.metakeywords || '', undefined,
				 }
	 }
        currentCategory.additionalFields[sideMenuSort] = categoryinfo[sideMenuSort]
	if (categoryinfo.parenturl !== '') {
	    context.displayValues.push(currentCategory)
	   }
        var sccategories = SC.CATEGORIES;
        var parentcate = _.findWhere(sccategories, { name: currentCategory.displayName })
        if (parentcate) {
          _.each(returnData, function (list1) {
             list1.categories = _.findWhere(parentcate.categories, { name: list1.displayName }) 
           })
        }
return returnData;
});