Add additional field to the Selection List in a Related Field

({
    extendsFrom: "RelateField",

    getSearchFields(){
        // get the fields from super;
        const fields = this._super("getSearchFields");
        if (this.getSearchModule() == "Contacts"){
            // append the contact fields for search results
            fields.push("account_name");
        }
        // return
        return fields;
    },

    /**
     * Searches for related field.
     * @param event
     */
    search: _.debounce(function(query) {
        var term = query.term || '',
            self = this,
            searchModule = this.getSearchModule(),
            params = {},
            limit = self.def.limit || 5,
            relatedModuleField = this.getRelatedModuleField();

        if (query.context) {
            params.offset = this.searchCollection.next_offset;
        }
        params.filter = this.buildFilterDefinition(term);
        
        this.searchCollection.fetch({
            //Don't show alerts for this request
            showAlerts: false,
            update: true,
            remove: _.isUndefined(params.offset),
            reset: _.isUndefined(params.offset),
            fields: this.getSearchFields(),
            context: self,
            params: params,
            limit: limit,
            success: function(data) {
                var fetch = {results: [], more: data.next_offset > 0, context: data};
                if (fetch.more) {
                    var fieldEl = self.$(self.fieldTag),
                        //For teamset widget, we should specify which index element to be filled in
                        plugin = (fieldEl.length > 1) ? $(fieldEl.get(self._currentIndex)).data("select2") : fieldEl.data("select2"),
                        height = plugin.searchmore.children("li:first").children(":first").outerHeight(),
                        //0.2 makes scroll not to touch the bottom line which avoid fetching next record set
                        maxHeight = height * (limit - .2);
                    plugin.results.css("max-height", maxHeight);
                }
                _.each(data.models, function (model, index) {
                    if (params.offset && index < params.offset) {
                        return;
                    }
                    // set empty additional text
                    let additionalText = ""
                    // append the additional data if the searchModuleContacts
                    if (self.getSearchModule() == "Contacts"){
                        const acc_name = model.get("account_name"); // get the account_name here
                        additionalText = ( acc_name ? ' (' + acc_name + ')' : ''); //set here
                    }
                    fetch.results.push({
                        id: model.id,
                        text: model.get(relatedModuleField) + additionalText //use the account_name here if its set
                    });
                });
                if (query.callback && _.isFunction(query.callback)) {
                    query.callback(fetch);
                }
            },
            error: function() {
                if (query.callback && _.isFunction(query.callback)) {
                    query.callback({results: []});
                }
                app.logger.error("Unable to fetch the bean collection.");
            }
        });
    }, app.config.requiredElapsed || 500),
})