Ltc_AdvancedTemplateHints is a module for Magento 2 that extends the default "Template Hints" feature.
It is largely based on the work of fbrnc and his Aoe_TemplateHints module for Magento 1
To display the template hints add ?ath=1 at the end of the URL and make sure the request IP is allowed in dev/restrict/allow_ips (Store > Configuration > Advanced> Developer > Developer Client Restriction > Allowed IPs)