Typed in
"Name1" into C2
"Name2" into C3
"Name3" into C4

Selected these three names and copied them down through cell C26

Using Data-filter-Advance filter
Action - copy to
List range C2:C26
Clicked the Unique records only and selected E2
Clicked okay

Results was
Name1
Name2
Name3
Name1

Any idea why Name1 was repeated?
Copied C2:C26 over to h2 (sorted the list) and all "Name1" are identical