The range of Scrying is "self", so the caster targets him/herself first
The spellcasting rules says that the target must be withing range:
The target of a spell must be within the spell's range
However, range of Scrying is "self", so initially the caster is targeting self, not the creature he/she is scrying:
Scrying
5th-leveI divination
Casting Time: 10 minutes
Range: Self
You can see and hear a particular creature you choose that is on the same plane of existence as you...
After you target self and cast the spell, the spell effect gives you an ability to "see and hear a particular creature you choose". The "target" mentioned afterwards means this "particular creature" and does not obey the general rule for targeting — it has its own specific rules based on the target familiarity.
Furthermore, RAW a clear path to the target is required when the spell affects the target:
A typical spell requires you to pick one or more targets to be affected by the spell's magic. A spell's description tells you whether the spell targets creatures, objects, or a point of origin for an area of effect
The Scrying spell does not affect the target, it "creates a sensor":
the spell creates an invisible sensor within 10 feet of the target
I guess it's another reason why "A Clear Path to the Target" might not be applied.
Third reason — the common sense. There is little or no sense in a scrying spell, that requires you to see the person you're scrying in order to work. If a DM adjudicate Scrying this way, nobody won't use this spell in their games.
Final verdict: No, the Scrying spell does not require you to have a clear path to the target.
Scrying is limited to targets on the same plane
The part of the scrying spell that lets you target a location says that you target a location "instead of targeting a creature". This indicates that unless otherwise noted, any the restrictions on which creatures you can target also apply to scrying on locations – the only thing that changes is the type of the target. This means that the requirement for the target to be on the same plane of existence applies to all valid targets for the spell.
Best Answer
Yes, you can.
The part of the scrying spell description about targeting a location says:
It doesn't specify that you must have seen the location physically; any form of "sight" is enough. It's a concentration spell, so you can't have multiple castings of scrying active at the same time, but you don't need to - you just need to have seen it at some earlier point. And per the earlier portion of the spell description:
As such, from a straightforward reading of the spell, you can indeed choose a location you have previously seen through the scrying sensor as the target for a new scrying spell.
The spell description doesn't specify how closely you must have seen the location, or how specific the location you choose must be. As such, this is something that's left to the DM to adjudicate.