For whatever reason it kept barking about (currentLayer.id), but I got it to work by defining what config name the user selected. I'm sure this code is ugly and inefficient as far as the logic but it works and I'm a noob.
var newlayerInfo = this.config.layers[newValue].name;
if(this.config.layers[newValue].name === "Subdivision"){
var subs = this.operLayerInfos.getLayerInfoById("Subdivisions_8362");
subs.setTopLayerVisible(true);
}else{
var subs = this.operLayerInfos.getLayerInfoById("Subdivisions_8362");
subs.setTopLayerVisible(false);
}
if(this.config.layers[newValue].name === "Tax Map"){
var tm = this.operLayerInfos.getLayerInfoById("TaxMap_5265");
tm.setTopLayerVisible(true);
}else{
var tm = this.operLayerInfos.getLayerInfoById("TaxMap_5265");
tm.setTopLayerVisible(false);
}
Thanks again Robert!