Using Object Mapping Category association will reduce the proposed component names for the Component Names View to only the restricted Object Mapping categories and their children. This is only working for all the children of a test case.
There are two ways to assign Object Mapping Categories to a test case. Either in the Test Case Browser select a test case from the project and select Edit OM association in the context menu. You can also do the same within the Test Case Editor when selecting the root node.
The Dialog which is opening is having one combobox and two trees with buttons between them. The Combobox shows which AUT is used for using the categories. Only one AUT can be selected at any time, if it is switched to another AUT all selected Categories will be removed. The left tree shows the available categories and the right shows the categories which are already selected. You can move the categories between both trees with the buttons between them.