I have never heard of the Circle web filter, so I looked through the Circle Support articles and found this:
Managing Custom Filters from Usage and History
The Usage and History sections allow you to add websites to each family member’s Custom Filters. From there, you can filter out sites that had previously been Allowed, or you can Allow sites that had been filtered out.
Adding a Custom Filter from Usage
Select Usage from a family member's profile, and tap any website listed on the Usage summary screen. Select Set as Allowed, Set as Not Allowed, or Set as Unmanaged. This will add the website to the Custom Filter list with the setting you choose.
Adding a Custom Filter from History
Select History from a family member's profile, and tap any website you would like to add to Custom Filters. Select Set as Allowed, Set as Not Allowed, or Set as Unmanaged. This will add the website to the Custom Filter list.
Adding a Custom Filter from the History of Filtered sites
Select History from the family member's profile, and tap Filtered from the options at the top of the History screen. Tap any website you would like to filter, and select Set as Allowed, Set as Not Allowed, or Set as Unmanaged. This will add the website to the Custom Filter list for that family member.
https://support.meetcircle.com/hc/en-us ... 0029052191