When you have too many friends on your Twitter list, you need to sort and put them into groups. Click on the group icon on the toolbar. Enter a name for your group - office, school, internet friends, etc. Now, check the boxes next to all the friends you want in that group. Click Save group. You can also filter friends by typing their name in the text field. A new pane will be created in Tweetdeck. Tweetdeck adds new panes when you create new groups or use any of the features.