Doubt to create a view using Organic Groups

Hi,
I am using Drupal 6 and the last version of views module. I want to create a view to show the nodes of a content type. This kind of content type can be published in one, two or more groups.

The problem is that when a node is published in several groups, also is published in my view as many times, as in groups has been published. So, I guess I have to create an argument but I don´t know how.

Anyone could help me?

Thank you!