Answer
You can filter the page's underlying List directly by appending an OData-style $filter to the page's own URL, referencing the List's actual field names and, for enumeration-typed fields, their fully qualified enum literal — for example, .../RequestsOverviewPage?$filter=CompanyId eq $[COMPANY_ID] and EmpNo eq $[EMP_NO] and Objstate eq IfsApp.AbsenceManagerHandling.HolidayRequestState'Confirmed' filters directly on an Objstate enum field using its fully qualified type and literal value, combined with dynamic $[...] parameter substitution for company/employee context. This lets you filter fields that aren't exposed on the page's own visible filter panel, as long as you know the underlying field name and, for enum fields, its correct fully qualified literal syntax.