CheckBox on UserForm to show Full list or Part list according to Criteria

[10shlomi10]

Good Day,

I wish to be able to show on ListBox , which I have on UserForm, all list OR part of the list, depending on CheckBox Click.
Meaning, I have a CheckBox which will be True/Checked when UserForm is load, and then ListBox will show only Row from data that has #N/A on specific column (On attached example it's column C) BUT Unique on other column, let say column A.
ColumnA | ColumnB
aa | #N/A
aa | #N/A
aa | #N/A
bb | #N/A
bb | #N/A

will show on ListBox:
aa |#N/A
bb |#N/A
etc'....

When the UserForm is already on screen, I want the ability to Un-Check the CheckBox and then the ListBox will be fill up with ALL data.

any help will be appreciated.

example File is on attached.

All the Best !