Even if there isn't a specific option to configure a router as a switch, in most cases you can simply just use the LAN ports and leave the WAN port unused to simplify your setup. Of course if you need the extended range of the wireless or for a number of other features, it may be necessary to configure multiple subnets, but technically, if properly configured, there are no reasons why you can't nest them.
Personally, I have 3 switches and 3 wireless routers in my home network, but to keep it relatively simple, all devices are connected to a central router so at most they are 2 deep, no third tier.