title: Specification builder doesn't recognize transient properties
body: <p>I'm trying to implement specification in one of my use cases.</p>
  <p><a href="https://i.stack.imgur.com/Lnb8M.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Lnb8M.png" alt="enter image description here" /></a></p>
  <p>As u can see in the function dateValueBetween, I'm trying to get from the root the  transient property valueDate. But when calling this service with real data it give the error downside.</p>
  <p>My original problem was how to call the builder.between method but the value I have is a String value and need to be parsed.
  but it seems that the first argument need to be a property of the table and not a function.</p>
  <p>How can I achieve my goal?</p>