Filter on incoming references by selecting the kind of incoming reference: 'Any', 'Object Descriptions', 'Sub-Object Descriptions', or 'Sub-Object Locations' and specify the amount of incoming references by clicking on the grey 'more' button.

Incoming references are listed per Object Type and/or Classification in a separate tab. Each incoming reference of another Object Type/Classification can be filtered on separately or together by using the Cross-Referencing option. Click the green 'filter' button to open an existing filter or a new (empty) filter to filter on the referenced Type/Classification.