Geometry conversion is… difficult to say the least. Strings are finite and only round once, but geometry suffers (benefits?) from having floating point conversion with all the underpaying mathematics to build the shape (so 3x for a point). As such Geometry is best compared with the underlaying values (strings in this case), or with methods which accommodate this difference.
The ‘base level’ of this comparison is easy enough to think through: if the point in list 1 and list 2 is the same, then the distance between the two will be 0, or near to zero with floating point concerns. Geometry.Distance to will make short work of getting the distance. == with tolerance or Math.Round and == will take care of the second bit, then it’s just a matter of filtering.
For more complex geometries a distance comparison won’t work as the distance from a hot dog and the bun it’s consumed in will be zero, but they certainly aren’t the same. Fortunately you can use this node to identify that the hotdog isn’t like the bun, but two identical hotdogs are in the same place in space: Dynamo Dictionary
Give it a shot as you guys are REALLY close (and now I really want to go grill up some dinner).