You can search for pages with Talk discussions using the Confluence Search:

Confluence Search field in the header

Use the standard Confluence Search field in the header to enter your query. 

You can use Confluence Search Syntax to refine your search.

 

The search queries syntax is the following:

QuerySearchExamples
macroName:talk
Find all Confluence pages with at least one Talk macro 
talk:"some text"By text in discussions

talk:release

talk:"do that ASAP"

talkUser:"User Name"By commenter (by user name, first name, last name or full name)

talkUser:asmith

talkUser:Alex

talkUser:Smith

talkUser:"Alex Smith"

talkUpdated:[yyyymmdd TO yyyymmdd]By talk update date rangetalkUpdated:[20141201 TO 20150201]
macroName:talkFor Talk macromacroName:talk

talk:"some text" AND talkUpdated:[yyyymmdd TO yyyymmdd] 

talk:"text 1" OR talk:"text 2"

talkUser:"User Name 1" NOT talkUser:"User Name 2" 

(variations are possible)

By several terms

talk:"do that ASAP" AND talkUpdated:[20141201 TO 20150201]

talk:change OR talk:modify

talkUser:asmith NOT talkUser:jclarks

Make sure to include your query in double quotes if it contains spaces.

Confluence Search Screen

Available in Confluence 5.9 and above

Instead of using search queries you can search Talk discussions by adding filters on the Confluence search screen.

Available filters: