Developing a global ER $($Entity$-$Relationship$)$ diagram requires us to integrate the various entities and their relationships from the localized ER diagrams you've provided. Given that we have four personas$$Marketing Specialist, Stay$-$at$-$home Parent, Film Student, and Software Developer$$each with unique data needs, the global ER diagram must be comprehensive enough to accommodate all these needs without data duplication.

Here's how we could conceptualize the global ER diagram based on the provided localized ER diagrams:

Entities:

Movie $($MovieID$,$ Title, Genre, Age Rating, Formats$)$

Cinemas $($CinemaID$,$ Location, Amenities, Facilities$)$

Booking $($BookingID$,$ UserID, MovieID, Showtime, Seat Selection, Discounts, Seating Preferences$)$

User $($UserID$,$ Preferences, Types like Marketing Specialist, Stay$-$at$-$home Parent, Film Student, Software Developer$)$

Events $($EventID$,$ Type, Date, Description, Exclusive Screenings$)$

Showtimes $($related to Movie and Cinema entities$)$

Notifications $($NotificationID$,$ linked to User and Event$)$

Community $($User posts, Discussions, Reviews$/$Ratings$)$

Relationships:

Movie "Shown In$"$ Cinemas $($M:N relationship$)$

User "Makes" Booking $(1$:N relationship$)$

User "Receives" Notifications $(1$:N relationship$)$

User "Participates In$"$ Events $($M:N relationship$)$

Cinemas "Offers" Showtimes $(1$:N relationship$)$

User "Interacts With" Community $(1$:M relationship$)$

Booking "Includes" Discounts $(1$:N relationship$)$

User "Has" Preferences $(1$:$1$ relationship$)$

Attributes:

Multivalued: User Preferences $($could include things like preferred genres, cinemas, etc.$)$

Composite: Location $($split into attributes like street, city, state, etc.$)$

Derived: Age Rating $($could be derived from the movie details$)$

Constraints:

Every booking must be associated with one user and one movie showing at a specific time in a cinema.

Cinemas can have multiple showtimes and facilities, but each showtime is unique to a cinema.

Users can have multiple bookings, notifications, and events, but each booking is unique.

Events could be linked to specific movies $($like premieres or special screenings$)$ or general cinema$-$related events.

We would also consider weak entities if there are any dependencies where an entity cannot exist without being associated with another. For example, a seat selection cannot exist without a booking.

To complete this task, we would need to visually draw out this ER diagram, ensuring we have the correct cardinalities and participations for each relationship, and avoiding the duplication of entities or attributes. The relationships would need to reflect the different roles each user persona plays in the system, with the necessary associative entities where M:N relationships are present.