JSFiddle - React, Tailwind, and code Playground

HTML

<div id="demo">

</div>

JavaScript

var arr = [{a:1,b:4}, {a:5}, {a:6}, {a:11}];
_.mixin({
   or: function(obj,arr,condition){
     return _.chain(arr).where(condition).union(obj).value();
   }
});
var result = _.chain(arr).where({a:1}).or(arr,{a:11,b:3}).or(arr,{a:2}).value();

document.getElementById('demo').innerHTML = JSON.stringify(result);