If you hit clear/cancel it will allow you to scroll through them all in one list. There is not a way to select a specific date range. Only a single day.
Insure the "selected cam only" icon is selected in upper right of clip viewer (a circle with a "1", turns green when selected).
Click on a live cam view of a cam that you want to un-protect or protect its clips; if you properly selected the "selected cam only" as directed above, only the clips for that one cam will appear in the clip viewer.
The protected clips will have a yellow padlock.
Click on a clip for the cam you want to un-protect; it should become highlighted to a light gray shade.
While holding down the <Control> key, LEFT click on each of the clips you want to un-protect; that will highlight the clip to a lighter shade of gray.
If you click on the wrong clip, making it light gray, just continue to press the <Control> and LEFT click on it again, reverting the light gray highlight back to a darker shade of gray, meaning that clip is NOT selected.
When you have the clips you want to un-protect highlighted light gray, RIGHT click on any of them and choose "un-protect" from the context menu.
You can use the same process with the <Control> key and LEFT click to highlight to light gray the un-protected clips then RIGHT click to select "protect" from the context menu.
Remember: whatever clip is highlighted LIGHT gray with a LEFT click will be the ones changed when you RIGHT click to select "protect" or "un-protect" from the context menu.
If desired go to a different cam and select the clips to add or remove protection. It sounds complicated but if you try it a few times it really isn't; it's a component of the old Windows Explorer use of the <CNTRL> and <SHIFT> keys to select files for copying, deletion, etc. that has been around since at least Windows 95 / mid 90's.