Allow to use fields of related items in automations in a way that the fields will not appear in items view

There is no doubt that the rollup fields and the automation functionalities are very powerfull. However, whenever an automation uses a value of a connected type it becomes somewhat inconvenient. Currently, the only way to do that is by using a rollup field. This way, the data required for the automation can be found in a field of the type for which the automation is defind. The problem with that is that rollup field always appear for all items of a certain type. This means that even if I create a rollup field that is only used in one or more automations and does not contain any valuable information for the user, the user will be forced to see this information in every item of that type. This makes finding the relevant information when viewing a certain item harder, and it will get harder and harder as more rollup field are defined.
I sujest 2 solutions:

  1. Add the ability to hide a certain field. This way, you can define as many rollups as needed without affecting the user experience.
  2. Allow the ability to access related items fields when defining an automation.

Personally, I thins that both solutions should be implemented. The first solution is probably easier to develop and thus should be the quick solution.

If I understand your request…
it is already possible to access the fields of related entities in automation formulas without having to create the lookup first.
Below is a rule that prefixes the name of a Task with the name of its parent Project: