Based on the available documentation, this specific configuration โ holding a property constant only between steps 2 and 3 while allowing it to change between steps 1 and 2 โ is not directly supported by Mixpanel's "Hold Property Constant" feature.
Here's why:
The Hold Property Constant feature in Funnels requires that the property remains the same value across all steps of the funnel. As the docs state:
"a user must perform the funnel events in the order you specified with the same property value"
Additionally, it can only be applied to properties that exist on all events in the funnel. [Hold Property Constant]
There is no built-in option to scope the constant property constraint to only a subset of steps (e.g., steps 2โ3 only).