First method: Using groups

You can open all sessions in a group with one click.

Assign a session into a group

1. Open session settings screen using the three dots menu
2. Specify Group for the session
3. Hit the Save button

Repeat this for all sessions which you want to start together.

Start all sessions in a group

Second method: Open all sessions for a website

You can open all sessions for a website with one click.

1. Switch to Show by Site view
2. Look for the website and hit the gear icon to open site menu icon and select Open all