To track your progress on the Lairs, use the collectible tab in the "M" (default) menu. That will show you the progress on each section of the map, and it will also blink in the general areas of other holes.
If you don't want to look for any of the collectibles yourself, feel free to use this amazing guide by Qrowley and thank him in the comment section
https://steamcommunity.com/sharedfiles/filedetails/?id=19971...