I was trying to configure the feature search for more than one (1) attribute on my feature layer. Currently, it is restricted to one attribute per layer, which is very limiting when trying to create a dynamic searchable widget. The work around is to load multiple feature layers just to create pre-defined searches using the WYSIWYG App Builder which ends up being confusing for the end user.
I have attached the email traffic from ESRI about the feedback that I had submitted online on the directions for configuring the feature search; you can find the intructions that I referenced ~> http://doc.arcgis.com/en/arcgis-online/create-maps/configure-feature-search.htm
web-appbuilder wysiwyg configure feature search Jennifer Wrightsell-Hughes