You would need to create a Data Explorer query for this and to write the query, you’d need SQL skills or know how to write SQL queries.
If Data Explorer doesn’t sound familiar to you, please see:
- Data Explorer Plugin - plugin - Discourse Meta
- What cool data explorer queries have you come up with? - howto / tips & tricks - Discourse Meta
If you still have questions about how to write a Data Explorer query, you can create a new support topic and tag it with data-explorer.