filter() returns all the elements in a list that comply to a predicate.
Arguments:
list: An expression that returns a list
variable: This is the variable that can be used from the predicate.
predicate: A predicate that is tested against all items in the list.
Example Query:
MATCH (a)
WHERE a.name='Eskil'
RETURN a.array, filter(x IN a.array WHERE size(x)= 3)