In order for your visitors' Confluence search queries to appear in your Google Analytics Console, you'll have to perform the following settings in your Google Analytics Admin Console:

Open the site search settings (described on and set the following:

Query Parameter: text

Strip query parameters: Checked

Site search categories: Off

After the changes are in effect, you should see site search results in your Google Analytics Console. Note that due to the latency in Google Analytics, this may take up to a couple of hours.