Hi dude

I think it's the same with one switch or 3 switch. According to your network, it if you want the switch above to be the DHCP Server.

The other switch only need to config the VLAN to make sure the traffic get into the correct VLAN as you wished.

I made this configuration for a school too 3 SSID, with 2 inside VLAN10 and 1 inside an isolate guest VLAN20 and multiples EAP connected to 2 SWITCHES

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1. ROUTER: you will need to setup your TL-ER (router) a route to transfer packet to second/tird/fourth/... IP-VLAN10 & 20 of your subsidiary SWITCHES.
2. SWITCH: as one from yours switch will be the DHCP server (not the router) you will need to USE DHCP relay with the others switch and have the same VLAN settings
3. EAP: SSID will need to be taggeg with VLAN according your choice of subnet linked with those SSID

If you have multiple switches, you need to tag the ports the same way on each switch and make sure they are tagged to the uplink trunk/interface. The APs will have unique IP addresses, but it won't matter which switch they are on if the ports are all setup the same. All vlans will use the same IP Helper addresses across all switches, so it won't matter.