network/roles/firewall/templates/networks.nft.j2

{% for family, family_prefixes in vrf_prefixes | groupby('family.value') %}
{% for vlan, vlan_prefixes in family_prefixes | groupby('vlan.vid') %}
set {{ vlan_prefixes[0].vlan.name }}{% if family == 6 %}/6{% endif %} {
    type ipv{{ family }}_addr; flags interval
    elements = { {{ vlan_prefixes | map(attribute='prefix') | join(',') }} }
}
{% endfor %}

{% endfor %}