You can search in the file opened in the viewer. See the following commands:
- Find (the Ctrl+F key): opens the Find dialog box where you can specify the text you are searching for and search options,
- Find Next (the Ctrl+N key): repeat searching,
- Find Previous (the Ctrl+P key): repeat searching but in the opposite direction.
You can find all described commands in viewer menu Search.
When you are opening Internal Viewer from the Find dialog, you may appreciate the following option: Set Find in the Internal Viewer to search grepped text from the Find Files dialog in the Configuration/Internal Viewer.