Internal filter


I am using MDEK1001 did some kind of experement where using 4 anchors in square 3x3.9m on a top of grid with 30x30cm clear LoS but inside a room
I calculate the error in this space for each point in the grid and what I notice that in case I change tag from postion A to B where the distance between them is 30cm in x or y direction the error will be high while if I hold the tag from position A and move around the space then return it to the B point the error will be lower
Numbers point of view is the error in case A will be around 30cm to 49cm while in case B for the same position it will be between 1cm to 20cm
my question is: after calculating the distances between the tag to each anchor, how the multilateration is done and is there any kind of filter before the final answer?