1. What is the problem? Be very detailed.
The attached example which is a hugely simplified example of what I am trying to do. I want to ask the third question (${university}) "Does the city have a university?" only if the place selected in response to the second question (${place_choice}) is a city. This "city" property I have defined in the choices tab in a column called "type". So what I am trying to work out is whether I can call the "type" column from the response to ${place_choice} in the "relevant" option for ${university}. So for relevant something like selected(${place_choice}, type = 'city').
Or perhaps there is another way of doing this without writing a very long-winded clause in the "relevant" column
Thinking of a workaround of your issue, since you already know which place is a city or town, a way to achieve that easily without changing much your design will be to introduce some preloaded data, then getting the type of place.
This reaches down to the underlying ODK XForms specification with an XPath expression that filters place entries to get the one matching your prior selection and then compares its type to 'city'. XLSForm could hide some of the complexity of building this kind of expression the same way that the ${} syntax does but it doesn't currently do so.