Querying first and last name with golang and mongo

Question

I'm having some problems with querying the first and last name with go and mongo, basically if I search for "Jonh " (with the whitespace) it doesn't work and "John Doe" neither, but if I search "John" or "Doe" it works.

func (user User) Prepare() bson.D {
    var filters = bson.D{}
    var arrayFilters bson.A

    if user.Search != "" {
        arrayFilters = append(arrayFilters, bson.M{"profile.firstname": bsonx.Regex(user.Search, "i")})
        arrayFilters = append(arrayFilters, bson.M{"profile.lastname": bsonx.Regex(user.Search, "i")})

        filters = append(filters, bson.E{Key: "$or", Value: arrayFilters})
    }


    filters = append(filters, bson.E{Key: "deleteddate", Value: 0})

    return filters
}

I found some solutions with aggregate + concat but couldn't really translate it to bson

Mongo document:

 "_id": {
    "$oid": ""
 },
 "email": "",
 "profile": {
    "firstname": "john",
    "lastname": "doe",
 },