You can create caps across ticket groups in the Event Dashboard>>Event>>Purchase Settings>>Ticket Caps. Click Add Another Cap and enter a value, then select the groups included in the cap. This will limit the number of tickets sold in all these groups combined to the value you entered. For example, if you set a limit of 100 tickets across two ticket groups, and you sell 100 tickets in one of those groups and 0 in the other, they will both be sold out.
You can also set limits across ticket levels (e.g., make 150 tickets available across two ticket levels). This setting is found in the Wizard>>Purchase (Step 3). Select the ticket group the ticket level belongs to and then Registration Caps.
If you want to feature the tickets remaining for your available tickets, you now have two different display options:
Limited Quantity with tooltip: Hide the number of tickets and show the details in a tooltip. This is useful when you are using advanced ticket caps across different ticket types and groups.
Number of tickets remaining: Show the number of tickets per ticket type. This is best when you have simple caps set up per ticket.
To customize your Remaining Ticket Information Display, navigate to Event >> Purchase Settings >> Settings on your Ticket Event Dashboard. Choose the setting that you would like, then click Save.