Sorry I dont speak english… I’m Turkish…
Hi
Sorry, my english is not good (french…) 
Data▸Filter▸Standard Filter▸Options allows to filter and eliminate duplicates.
But beware this is to exclude duplicate rows: it excludes only rows for which all columns are duplicated.
To filter rows from one column simply select only this column.
You can also create a “test” column with the COUNTIF function in a formula. See DoublonsCorr.ods.
This short video (in French) explains the various possibilities.
Regards