distances.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 }
]

function distances(input) {
  return input.filter(i => i.type !== 'a').reduce(({near, medium, far}, currVal) => {
    return ({
      near: currVal.distance >= 0 && currVal.distance < 4 ? [...near, currVal] : near,
      medium: currVal.distance >= 4 && currVal.distance < 8 ? [...medium, currVal] : medium,
      far: currVal.distance >= 8 && currVal.distance <= 10 ? [...far, currVal] : far
    })
  }, { near: [], medium: [], far: [] })
}

distances(input)