Further narrowing of the audience can be done based on interests and behaviors.
Currently,
TikTok advertising dashboard offers 15 interest groups, which are broken down into more specific interests. User behavior is determined depending on the content they interact with on TikTok. Note that only content in English and Japanese is considered. In the settings, you can select the type and period of interaction (full view, like, comment, repost within 7 or 15 days) with videos from a particular category. There are many more categories than interests.
For instance, the "Lifestyle" interest includes the "Food" interest, which in turn is broken down into categories like "Food and Cooking", "Mukbang and Tasting", and "Beverages and Their Preparation".
If you're promoting a mobile app, targeting can be limited by the operating system, OS version, connection type, mobile carrier, and the price of the user's mobile device.