Proper way to access your new filter for all projects is to use the organizer and copy the filter to the global.mpt. Aritfacts from your global (views, tables, filters, groups, etc) become available for all projects. Open only the project that has your custom filter, select tools / organizer, select the Filters tab, and copy the custom filter (probably from the right side) to the global (probably the left side. Let me know if you have any addtional questions.