Thread:Project:Support desk/find text for section Template:Q2A:module=homepage/reply

Below the edit area there's a section named "templates used on this page" (you may need to hit preview first if you're editing a section). It will give you links to the template.

However, it could be that the wiki uses a custom extension and Q2A is a sort of parser function that gets the contents from an external source. In that case, you won't find it in the templates used on this page section.