Planner | Overview filters | Sub activities cannot be filtered when lacking the main activity

I am writing to request an enhancement to the Planner system. Currently, when using filters in the Overview section, users are required to know the name of the main activity in order to select a sub-activity. This can be frustrating and time-consuming, especially when working with a large number of activities.

I would like to request the addition of a new feature that allows users to select sub-activities in the filters without having to know the main activity name. Currently, whereas you can see sub-activities, when you apply the filter returns an empty "search". However, in case you add and the main activity, it returns both of them in the search result (filtered result)

I believe this enhancement would greatly improve the user experience and efficiency of the Planner system. Thank you for your time and consideration.

Here is a video that I have recorded for better explanation of the issue: https://watch.screencastify.com/v/tt27pntJwpPoqC5dDsJZ