Yes you can! You can search for all Records within a Category for editing or other purposes.
1. Go to the Main Menu > Records
Alternatively, go to a specific account, then under the first five Records tap on 'Show more'
2. Tap on the Filter icon, then 'Instant filter'. Choose whichever Category* you want, then tap on √.
3. When your desired Records are displayed, long tap on one Record, which will highlight it. Then you can tap on other Records, then 'Edit'. When you have finished, save your changes with the √.
*Note: These instructions apply for Labels or other identifiers, not just Categories!