breadperday.twig

{% set bread = craft.entries({ section: 'bread' }).limit(null) %}

{#
 # Users with bread on 3 days
 #}
{% set users3Days = craft.users({
    group: 'customers',
    relatedTo: [
        'and',
        { targetElement: bread, field: 'breadForMonday' },
        { targetElement: bread, field: 'breadForWednesday' },
        { targetElement: bread, field: 'breadForFriday' }
    ]
}) %}

{#
 # Users with bread per weekday
 #}
{% set usersMonday = craft.users({
    group: 'customers',
    relatedTo: { targetElement: bread, field: 'breadForMonday' }
}) %}

{% set usersWednesday = craft.users({
    group: 'customers',
    relatedTo: { targetElement: bread, field: 'breadForWednesday' }
}) %}

{% set usersFriday = craft.users({
    group: 'customers',
    relatedTo: { targetElement: bread, field: 'breadForFriday' }
}) %}

{#
 # Users with bread on 1 day (grouped per weekday)
 #}
{% set usersIdsMonday = usersMonday.ids() %}
{% set usersIdsWednesday = usersWednesday.ids() %}
{% set usersIdsFriday = usersFriday.ids() %}

{% set usersOnlyMonday = craft.users({
    id: usersIdsMonday|without(usersIdsWednesday)|without(usersIdsFriday)
}) %}

{% set usersOnlyWednesday = craft.users({
    id: usersIdsWednesday|without(usersIdsMonday)|without(usersIdsFriday)
}) %}

{% set usersOnlyFriday = craft.users({
    id: usersIdsFriday|without(usersIdsMonday)|without(usersIdsWednesday)
}) %}

{#
 # Users with bread on 1 day
 #}
{% set users1Days = craft.users({
    id: usersOnlyMonday.ids()|merge(usersOnlyWednesday.ids())|merge(usersOnlyFriday.ids())
}) %}

{#
 # Users with bread on 1, 2 or 3 days
 #}
{% set usersAnyDay = craft.users({
    group: 'customers',
    relatedTo: { targetElement: bread }
}) %}

{#
 # Users with bread on no day at all
 #}
{% set users0Days = craft.users({
    id: 'and, not ' ~ usersIdsAnyDay.ids()|join(', not ')
}) %}

{#
 # Users with bread on 2 days
 #}
{% set users2Days = craft.users({
    id: usersAnyDay.ids()|without(users0Days.ids())|without(users1Days.ids())|without(users3Days.ids())
}) %}