Use ‘List/segment membership’ as the condition to check whether contact in the running journey belongs to a particular list/segment or not. 

For example - Use this condition when you want to qualify a contact who belongs to the active users segment based on email opens and send a special discount campaign to reward them. 

Key steps -

Step 1: Drag and drop ‘List/segment membership’ card from the left panel. 

Step 2: Connect it to the desired card in the journey. 

Step 3: Click on the ‘List/segment membership’ card to open the right panel. 

Step 4: Select the list/segment from the dropdown. 

Step 5: Click on the ‘Save’ button to complete the configuration. 

This would mean, that whenever a contact reaches the ‘List/segment membership’ condition, it would check for presence in the list/segment and qualify contacts into YES and NO routes in the journey. 

It is recommended to add a delay of ~10 mins before the list/segment membership block for the case where the contact is getting added to the said list/segment via an action in the current journey. 

This is to ensure that the list or segment being used in the condition gets accuartely updated up till now