The usernames of the inferred topics for a story that is receiving comments, reshares, or likes. Usernames appear in the URL of a Facebook page, for example, in this case it is Lamborghini: https://www.facebook.com/Lamborghini.
Note: while these are labeled as usernames in the Graph API output, they are always Pages. The usernames of users (as opposed to Pages) are not available for filtering or analysis.
Topics are individual items in the Facebook social graph. A topic can be referred to with a FBID (Facebook id). Please refer to Namespace Families for further information.
See also: fb.topics.username.
Filter for comments, reshares, or likes on stories where the inferred topics for the story include the username Lamborghini:
fb.parent.topics.username == "lamborghini"
Target service: PYLON for Facebook Topic Data
Tokenized for query filters: No
Interaction filter: Yes
Analysis target: No
Query filter: No
Child analysis target: No