To change this filter, you will need to go to the Content Type of the page that you are selecting a thumbnail for.
- Go to Content > Select CMS.
- Click Content Types > Select More.
- Click the Content Type of the page that you are selecting a thumbnail for.
- Click Edit for the Fields section.
- Right click on the dropdown section of the Thumbnail Image field > Select Field Properties.
- Click on New Filter or Browse Filters next to "Choose a content filter."
- If you click on Browse Filters, you will got a pop-up that will let you select different filters to apply to this field. Choose the field(s) that you would like to have included in this filter. Click OK
- Click OK again in the field properties window.
- Click Save.