In Summit, you can create custom groups to separate your colleges/schools, which can be used in the analysis zones. For example, if in your group there are some consortium schools you could group those together, or if you had both schools and colleges in your group you might want to group them separately. 

To create a school/college group, first navigate to the Group Setup Management tab and click Analysis Setup.

Then click the Add A Group button:

This will open a pop-up where you can name your group and select the schools and colleges from the drop down list. Once selected, press Add Group.

Once the group is added, it will appear in the list and you can press Save Groups to finish.