So I've browsed through the topic and could not find a similar configuration.

The manager will be RB2011UiAS and the the AP wAP ac.
There is one bridge on the RB2011 and no DHCP server. The AP will not be connected directly to any of the RB2011's ports so I cannot assign a DHCP to a specific port.

The question is how can I set up CAPsMAN so that there are two WLANs for guests and employees both with DHCP servers?

Use multiple vlans to separate your stuff.

Add a bridge interface and tie DHCP to that? I guess it depends on your CAPsMAN datapath forwarding. If it's local, you can run your DHCP server on the CAP. If it's remote, you'll need DHCP on something with L2 connectivity to the CAPsMAN device's bridge.