Hi there,

Currently, for Advance search, you only can search fields on assigned categories/profiles types only.

Having said that, it would best if you could submit your feature request regarding this simply by creating a new ticket on the forums, and set it to "Feature Request" so everyone else on the site could vote for it as well. The team will usually prioritize features that are in popular demand during the development process of the next major release.

Thanks for your understanding.