Similar to how you can track expenses by category, you can track event expenses by adding a label to your transactions and than use that as a way to filter your data.
You'll need to create a new splits view in order to better filter your data.
<aside> 💡 What are splits?
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Next step is to add a custom filter to your view, similar to what's shown on this image:
The important thing is to add the type of accounts you want to filter for (ie. expenses or income) and the label you created for your event.