What exactly you want to retrieve ? Can you give an example of your dialog with the fields and node structure with properties. It will help to give you more exact response. To answer you in a simple way , if you have a dialog with a text field with name = ./title ; to fetch that value from node you can write the below line in your HTL file
${properties.title} , where properties is a global object for ValueMap API . Read more here HTL Global Objects .