how to split a map based on user input value

hi, 

I am trying to split a map based on user input 

local!data: {
a!map(id: 1, name: "Alice", age: 10, city: "New York",school:"NewYork"),
a!map(id: 2, name: "Bob", age: 12, city: "Los Angeles",school:"NewYork"),
a!map(id: 3, name: "Charlie", age: 13, city: "Chicago",school:"NewYork"),
a!map(id: 4, name: "David", age: 14, city: "Houston",school:"NewYork")
},

if I give input : age 

I should get two 

local!data1:{

a!map(id: 1, name: "Alice", age: 10, ),
a!map(id: 2, name: "Bob", age: 12, ),
a!map(id: 3, name: "Charlie", age: 13, ),
a!map(id: 4, name: "David", age: 14, )}  and 

local!data2:{a!map(city: "New York",school:"NewYork"),

a!map(city: "Los Angeles",school:"NewYork"),
a!map(city: "Chicago",school:"NewYork"),
a!map(city: "Houston",school:"NewYork")}

is there a way to achieve this , I tried ldrop and rdrop, it doesnt give output as expected