Enter from the left menu: Tools > Keyword Suggestions.
You'll get to the suggestions section, where you can select a URL at the top left and get keyword suggestions for each one of your keywords.
Click on keywords you want to add in the left box and move it to the right box, than when finished click "Add Desktop/Mobile/Local Finder" on the bottom, according to the tracking type you need.
It will take you to the Advanced Add, set the wanted tracking settings and save (Add).
Read here more about the Advanced Add.
You can get to the Keyword Suggestions directly from URL View by clicking the magnifying glass icon in the top-right corner of each URL box.