How Do I Get A Chart Showing The Number Of Instances Of Different Standardized Assignees From A Patent’s Citation List?

The method of doing this involves the use of Workspaces.

Firstly, you'd need to add all the citation data for the patent to a Workspace which can be done by going to the "Save All To Workspace" option found in the "Citation" tab when viewing a patent.

Once you've added these patents to a new folder within a Workspace, click on the "Custom Analysis" icon found near the top of the Workspace page.

Next, select the folder you would like you would like to bring into custom analysis:

In custom analysis, select the option of "Top Standardized Current Assignee(s)" from the "Assignee" drop-down menu and click the option of "Excel" given when hovering over the "Export" icon.