Distance.js

const input = [
  { type: 'a', distance: 5 },
  { type: 'c', distance: 3 },
  { type: 'b', distance: 6 },
  { type: 'c', distance: 12 },
  { type: 'b', distance: 1 },
  { type: 'a', distance: 5 },
  { type: 'b', distance: 6 },
  { type: 'a', distance: -1 },
  { type: 'c', distance: 9 },
  { type: 'd', distance: 10 }
]

// Filtering useless types
const filterType = o => o.type !== 'a'

// Filtering without distance (for safety)
const filterNoDistance = o => o.hasOwnProperty('distance')

// Reduce by distance, ignore < 0 and > 10, could be a third filter
const reduceDistance = (acc, o) => {
	if (o.distance < 0 || o.distance > 10) return acc
	
	if (o.distance < 4) {
		acc.near.push(o)		
	} else if (o.distance < 8) {
		acc.medium.push(o)		
	} else {
		acc.far.push(o)
	}
	
	return acc  
}

const accumulator = {
	near: [],
	medium: [],
	far: []
}

const output = input
	.filter(filterType)
	.filter(filterNoDistance)
	.reduce(reduceDistance, accumulator)