Hi Michele,
Filters are stored in DB table UJA_FILTER. They are not expanded there, but stored in XML format. So, you don't have to change them every time Dimension changes.
This is true that filters are user dependent. If your users don't change frequently you can create a filter for one user and then copy that record in the table for all other users. This will require a small ABAP program, but it should run only when new user should have access to that filter.
Would such approach work for you?
Regards,
Gersh