JAVASCRIPT

mongoose filter by multiple fields

router.get("/Search", authenticateToken, async (req, res) => {
  let search = req.query.tearms;
  
  // Create expression
  var re = new RegExp(search, "i");
  let find = {};
  let find2 = {};
  if (search != undefined && search != "") {
	//This all are the fields that will used as match
	find = {
      $or: [
        { firstName: { $regex: re } },
        { lastName: { $regex: re } },
        { username: { $regex: re } },
      ],
    };
  }
  let dataSearched = await accounts
    .find(find)
    .select("firstName lastName username profileImage")
    .limit(10);
  res.json(dataSearched);
});

Mongoose search multiple fields

var re = new RegExp(req.params.search, 'i');

app.User.find().or([{ 'firstName': { $regex: re }}, { 'lastName': { $regex: re }}]).sort('title', 1).exec(function(err, users) {
    res.json(JSON.stringify(users));
});