Lindsey, This will only work when you have same type of text-key available in text-editor. Without adding text-keys, you cannot set title using context-object page.content.head.setTitle.
Lets suppose in below code when you split "selectedLabels" and there will be two labels with label names "label1" and "label2".
<#assign labelListParam = webuisupport.path.rawParameters.name.get("forum","")>
<#assign selectedLabels = labelListParam?split(",")/>
So for "forums" cutom page your text-key for the title will be:
page.forums.label1.title = The Title of the page with name label1
page.forums.label2.title = The Title of the page with name label2
