Limit candidates to those with certain properties

Any way to limit the candidates to nodes with certain properties?

(I do need to see the entry content while doing the helm search, so I suppose helm-org-ql is not an option...?)

Big picture of what I'm trying to do: I have a file where each top level node has two sub-nodes: Theorem and Proof. I would like to do searches that are limited to only Theorem nodes. I suppose I could add a "theorem" tag on each Theorem node and add it to each search query, but was hoping to use properties instead.