Before you can add custom filters in a gallery collection, you must make them available in Studio Settings.
Steps to make custom fields available in Gallery:
- Navigate to Studio from the global navigation menu.
- Navigate to Custom Fields tab under Settings on the side navigation bar.
- Select the option to Display in Studio Preview and Gallery for all desired custom fields.
- Click Save Changes anywhere on the page.
Note: This will also make the custom fields viewable in Studio Preview if applicable to the content asset you are previewing.
Click here to learn how to add the Custom Filter to a Gallery Collection.