You can create a custom web part for drop down selection and bind the data using code something like this and call it on OnPreRender event.
var familyCategories = CategoryInfoProvider.GetChildCategories(familyParentId, siteId: SiteContext.CurrentSiteID);
var familyCatList = familyCategories.ToList();
var defaultFamilyItem = new CategoryInfo();
defaultFamilyItem.CategoryDisplayName = "Product Family";
familyCatList.Insert(0, defaultFamilyItem);
drpFamily.DataSource = familyCatList;
drpFamily.DataTextField = "CategoryDisplayName";
drpFamily.DataValueField = "CategoryID";
drpFamily.DataBind();
You can follow this link for help. Place this custom filter web part on the page. Below that add repeater web part and add this filter name in Filter name property of repeater.