I have been working with Nintex workflows for a long time now and have only just started using this action.  It is so simple but so powerful and has saved me doing this painful step in a lot of my workflows:

Scenario

I have a workflow that runs for all types of users entered into a list.  Most of the workflow is relevant to all types of users but there are some things that I would like to be done only if the user type is Employee.  Yes, I could use a Run If action, but I am using this fairly simple scenario to explain the filter action.

The Filter Action

As opposed to a Set a condition action where only one branch is executed, or a Run if action where the contents are run only on a condition being met, this action literally only executes the actions below it if the condition is met, otherwise the workflow is ended.  No need to add actions to a Run if container, or to add actions to one branch in a Set a condition action and an "End workflow" action in the other!

Action Configuration

Very similar to the Set a condition and Run if actions, you can specify:

• Condition:  what you are comparing (i.e. current item, variable, metadata etc)
• Comparison:  equals, not equals, contains, greater than etc.
• AND/OR conditions

For my specific example I have the configuration as follows:

I have designed a lot of my previous workflows using the very first image on this post but will have to keep the filter action in mind going forwards as it does the same thing and is often overlooked!