JSFiddle - React, Tailwind, and code Playground

JavaScript

function myFuzzyComparator(baseValue, range) {
  let min = baseValue - range,
      max = baseValue + range

  return function(x){
    return x > min && x < max
  }
}

// test:

let testValues = new Array(100)
    .fill(0)
    .map(v => Math.round(Math.random() * 200))

let cmp1 = new myFuzzyComparator(175, 5)
let cmp2 = new myFuzzyComparator(100, 20)

let near175 = testValues.filter(cmp1)
let near100 = testValues.filter(cmp2)

document.body.innerHTML += '<h3>175 ± 5</h3>' + near175.toString() + 
                           '<h3>100 ± 20</h3>' + near100.toString()