At the top of all main pages in ZERO, there is a filter and search dropdown area. On the Feed, you will see a dropbox box with the text "Apply filter or search...". 

1. Click on this box  at the top of the Feed.

2. From that dropdown field, select the types of filters you would like to apply to the Feed. These include Post Status, Date Range, Risk Level, and Tags. You can select multiple filters at once as well.

3. Finally, you can use this same field to search for any custom keyword you'd like, including author name.