Question about extension point .workitem.common.model.IWorkI

If i use this part of code
This code extend both the pop up menu in research work-item view and the menu present in work item presentation next to the name of the work item. How can I do that the menu is visible only in the second case?
<extension>
<objectContribution>
<action>
</action>
</objectContribution>
This code extend both the pop up menu in research work-item view and the menu present in work item presentation next to the name of the work item. How can I do that the menu is visible only in the second case?