See 3.13 in the Mandate
Local Support operates off the concept that as a Home Village (should be but doesn't have to be the Home City) becomes more cultured and engaged with the populace, the glory of the Clan begins to attract followers. These are locals who live in each hex. Once the cultural value of the Home Village reaches a point (Cultural Skill Threshold of 3), they gain the ability to start constructing Longhouses. Longhouses are locations where locals can congregate and act as a focal point for interactions between the Locals and the Clan.
As the smallest settlement, Longhouses have a few guards and have some unemployed locals who are looking for jobs.
Later, as the Cultural Skill Threshold rises, the Clan gains access to Hamlets, then LS Towns and then LS Cities (At Cultural Skill Threshold of 10).
However, because Local Support is an initial attempt at more organic growth, you can't just construct directly to City. It requires growth. As such, after getting 3 Longhouses and having unlocked Hamlets via its Cultural Skill Threshold, the Clan may then upgrade a Longhouse to a Hamlet by building some additional improvements (basically some support structures generically called Hamlet). This upgrades one of the three Longhouses to a Hamlet leaving the network to have 2 Longhouses and 1 Hamlet. Every Hamlet must be supported by 2 longhouses at the end of the turn. Longhouses support Hamlets which supports LS Towns which supports LS Cities and which eventually support larger settlements.
Hamlets are like Longhouses in that they provide built in guards and also have unemployed Locals ready for hiring.
Once a Cultural Skill Threshold of 6 is reached, the Clan unlocks Towns. This enables a Clan to upgrade 1 Hamlet into a LS Town by building 10' stone walls and a well. Once a Clan has 3 Hamlets, it may upgrade a LS Hamlet into a LS Town. Like Hamlets, LS Towns need support but they need support from 2 Hamlets. So every LS Town will have 2 Hamlets supporting it and every Hamlet will have 2 Longhouses supporting them. So at a minimum, a LS Town will have: 1 Town, 2 Hamlets, 4 Longhouses :at the end of the turn.
All LS Towns provide additional guards (100) plus due to the size of the town, they send over enraptured workers to the cultural mecca that is the Home Village in the way of 200 Auxiliaries upon completion of the Town and every Month 1 of the year. They also supply 50 Gold per town in tithes and supporting the arts and defense. LS Towns also have a larger pool of unemployed Locals to hire (200).
Additionally, LS Towns may be of one of 3 types:
At Cultural Skill Threshold 10, a Clan gains the ability to build LS Cities. A LS City requires 2 LS Towns (of any type) supporting it at the end of the turn. LS Cities offer a great amount of benefits in the way of Local Hiring (1k per month), Auxiliaries (based upon the number of settlements), Actives (based upon the number of settlements) an Commodities:, Type Gold and amount based upon number of settlements.
Now, some other stuff:
In addition to needing to reach Cultural Skill Threshold for each type of settlement, a Clan is limited to a total number of settlements equal to the Clans combined skill levels in all cultural skills.
(445 - 2022-08-26 ref)