You create inter vlan rules that allow connections from your main vlan to the other vlans, but only allow established and related traffic from the secondary vlans back to the main vlan.

I have a separate vlan for IoT and guests but punch holes for contact back to my HomePods(main vlan) for my Ecobee thermostat (IoT vlan) to contact so my kids can use Siri to get the weather in the mornings, and for guests to use the printer, that sort of thing.