When viewing the Endpoint Agent Overview, in the filter there is an option to sort by the "Configuration Version":

This "Configuration Version" is the version of the Policy that has been pushed out to the Endpoint Agent.

The version can be seen when looking at the edpa0.log for an entry similar to:

Using the value for the Configuration_Update, 1279226874592 in the example above, you can filter all Endpoint Agents that have been updated with this version of the Policy.