It creates the groups properly, but does not assign users to them.

pillars_users_group1.sls

{% from "users/map.jinja" import users with context %}

group1:

  mbarnett:
    fullname: Melissa Barnett
    home: /home/mbarnett

pillars_users_group3.sls

{% from "users/map.jinja" import users with context %}

group3:

  ehunter:
    fullname: Ethan Hunter
    home: /home/ehunter

pillars_users_groups.sls

groups:
  {% if grains['os'] == 'OpenBSD' %}
  group1:
    - wheel
  group3:
    - 3group
  {% elif grains['os'] == 'Debian' %}
  group1:
    - 1group
  group3:
    - sudo
  {% endif %}

pillars_users_map.jinja

{% set users = salt['grains.filter_by']({
  'Debian': {
    'adm_group': 'sudo',
  },
  'OpenBSD': {
    'adm_group': 'wheel',
  },
}, merge=salt['pillar.get']('users.lookup')) %}

salt_users_group1.sls

{% for user, args in pillar['group1'].iteritems() %}
{{ user }}:
#  group:
#    - present
  user.present:
    - home: {{ args['home'] }}
{% if 'password' in args %}
    - password: {{ args['password'] }}
{% if 'enforce_password' in args %}
    - enforce_password: {{ args['enforce_password'] }}
{% endif %}
{% endif %}
    - fullname: {{ args['fullname'] }}
    - groups: {{ salt['pillar.get']('groups:group1') }}
#    - require:
#      - group: {{ user }}
 
{% if 'key.pub' in args and args['key.pub'] == True %}
{{ user }}_key.pub:
  ssh_auth:
    - present
    - user: {{ user }}
    - source: salt://users/{{ user }}/keys/key.pub
{% endif %}
{% endfor %}

salt_users_group3.sls

{% for user, args in pillar['group3'].iteritems() %}
{{ user }}:
#  group:
#    - present
  user.present:
    - home: {{ args['home'] }}
{% if 'password' in args %}
    - password: {{ args['password'] }}
{% if 'enforce_password' in args %}
    - enforce_password: {{ args['enforce_password'] }}
{% endif %}
{% endif %}
    - fullname: {{ args['fullname'] }}
    - groups: {{ salt['pillar.get']('groups:group3') }}
#    - require:
#      - group: {{ user }}
 
{% if 'key.pub' in args and args['key.pub'] == True %}
{{ user }}_key.pub:
  ssh_auth:
    - present
    - user: {{ user }}
    - source: salt://users/{{ user }}/keys/key.pub
{% endif %}
{% endfor %}

salt_users_groups.sls

{% for group, args in pillar['groups'].iteritems() %}
{{ args.pop() }}:
  group:
    - present
{% endfor %}

salt_users_init.sls

include:
  - users.groups
  - users.group1
  - users.group3

state.show_sls users

# salt obsd1 state.show_sls users 
obsd1:
    ----------
    3group:
        ----------
        __env__:
            base
        __sls__:
            users.groups
        group:
            - present
            ----------
            - order:
                10001
    ehunter:
        ----------
        __env__:
            base
        __sls__:
            users.group3
        user:
            ----------
            - home:
                /home/ehunter
            ----------
            - fullname:
                Ethan Hunter
            ----------
            - groups:
            - present
            ----------
            - order:
                10003
    mbarnett:
        ----------
        __env__:
            base
        __sls__:
            users.group1
        user:
            ----------
            - home:
                /home/mbarnett
            ----------
            - fullname:
                Melissa Barnett
            ----------
            - groups:
            - present
            ----------
            - order:
                10002
    wheel:
        ----------
        __env__:
            base
        __sls__:
            users.groups
        group:
            - present
            ----------
            - order:
                10000