Recover hidden videos on iPhone

Hidden videos don't need recovering as they are in the Hidden Album of the Photos app and access with FaceID/Passcode.

If you deleted a video, they can be recovered from the Deleted album for 30 days. After 30 days or if they are deleted from that album, then they are no longer recoverable.

The Hidden Album is available in the Utilities section near the bottom of the Photos window:

(Unless it was moved with "Customize." In that case, look in the Customize menu.)

In Hidden, when you select a picture, tap the (•••) More button to get this menu:

and choose "Unhide."

Then the picture will disappear from the Hidden album, and it will reappear wherever it was before-- in the Library, for instance.

Does this work for you?