You're correct that in an Insights report, you can filter an event like “day_tap” by the property “selected_day” (e.g., only include events where “selected_day” is “monday”). However, when creating a custom event in Mixpanel, the property filter options are more limited and are primarily designed for filtering on date/time properties, such as “last”, “between”, “on”, “before”, “since”, or “in the next” ranges.
The knowledge sources confirm that custom events can be created by combining events and optionally filtering them by properties, but they do not mention support for filtering by arbitrary property values (like “selected_day” = “monday”) when defining a custom event. The available filters for custom events are focused on time-based properties, not categorical or string properties like days of the week. This limitation is reflected in the UI options you described and is not contradicted by the documentation:
A custom event is a virtual event that was created from one or more events, optionally filtered down by a particular set of properties, and given a name.
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You can create an event based on a filter on another event (“Purchase” where Country = “US” -> “US Purchases”)
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Select the events and properties you’d like to include.
Custom Events: Combine multiple events for analyses
However, the documentation does not provide details on filtering by non-date properties when creating custom events, and your experience matches the current UI limitations.
Workaround:
If you need to analyze “day_tap” events where “selected_day” is “monday”, you can apply this filter directly in your Insights report, rather than as part of the custom event definition. Alternatively, you can create a custom event for “day_tap” and then filter by “selected_day” in your reports.
Summary:
- Custom event property filters are limited, mainly to time-based filters.
- For non-date property filters (like “selected_day” = “monday”), use filters in your reports, not in the custom event definition.
If you need more advanced filtering as part of the event definition, this is currently not supported according to the available documentation and UI behavior.
If you have further needs, you may want to provide feedback to Mixpanel or check for future updates to custom event filtering capabilities.
