What level of knowledge constitutes being familiar with a location for clerics casting Find the Path?

Question

In the answer to this question it is determined that, RAW, a cleric only needs the 100gp of divinatory tools and a component pouch to cast Find the Path.

The text to Find the Path includes

This spell allows you to find the shortest, most direct physical route to a specific fixed location that you are familiar with on the same plane of existence.

Using the RAW answer linked above, how does a Cleric become familiar with a location? Do they have to visit it? Hear about it? See it in a divinely-inspired vision? See it through a magic mirror, or a mundane spyglass? How do we define being familiar with something and where exactly is the line where something becomes familiar?

Answer 1

It's up to the DM, but the teleport spell gives some insight.

Unfortunately, "familiar with" is given no clear or objective definition in the rules. However, the teleport spell gives some insight, as familiarity plays a role in that spell's success:

"Very familiar" is a place you have been very often, a place you have carefully studied, or a place you can see when you cast the spell. "Seen casually" is someplace you have seen more than once but with which you aren't very familiar. "Viewed once" is a place you have seen once, possibly using magic. "Description" is a place whose location and appearance you know through someone else's description, perhaps from a map.

Obviously, the "very familiar" category as described here qualifies for find the path, and "seen casually" seems to qualify as well - "not very familiar" still implies some level of familiarity.

"Viewed once" is the tough one. I have had my players use scrying to spy on an NPC, and then try to use find the path to get there. On one occasion, they recognized the location, and though they had never been there and only seen it through scrying, they were aware of the rough geographical location, so I let them use find the path. They tried this another time, and had no idea where the location seen through scrying was, so I did not allow them to use find the path.