Is there a way to pull multiple values from a dropdownformfield

Question

I am building a flutter application that has a dropdownformfield. I can get one value from the dropdown but would like to get multiple values.

my Data Model is like below

    class Users {
     final String uid;
     final String firstName;
     final String lastName;
     final String phone;

  Users(
      {required this.uid,
      required this.firstName,
      required this.lastName,
      required this.phone});
}

I get data from firestore and convert it into a list for the dropdown like this

        final List<String> users = snapshot.data!
            .map((user) => '${user.firstName} ${user.lastName}')
            .toList();

and set the selected value like so:

                    onChanged: (val) {
                      setState(() {
                        selected = val;
                      });
                    }),

This however captures the first and the last name but I would like to get the uid as well.

Anyone know how to do this?