In the extension, call the PLP container and then modify the displayValues.
plp.addToViewContextDefinition('Facets.FacetedNavigationItemCategory.View', 'displayValues', 'array', function(context) {
var categoryinfo = plp.getCategoryInfo();
console.log("categoryinfo", categoryinfo);
var currentCategory = {
displayName: categoryinfo.name,
isActive: true,
label: categoryinfo.name,
link: categoryinfo.fullurl
}
if (categoryinfo.parenturl != "") {
context.displayValues.push(currentCategory);
}
return _.sortBy(context.displayValues, 'displayName');
});