You can create additional columns in your document library to further specify and categorize. Adding a column will help your team make the most out of multiple views for your library.
From the Library page, you must select and open the library that you wish to add the column to.
1. From the Settings menu > click Create Column.
2. In the Name and Type section, enter the name you want to have in the Column name box.
3. Under The type of information in this column is > select the information type that is going to be described in the column you are creating.
4. In the Additional Column Settings section > type a description in the Description box (this is optional).
5. To allow the new column to be automatically viewed when anyone first opens a list or library, select Add to default view.
6. Click Ok.