Join the desired Group
Navigate to your Gmail account
Go to settings → see all settings → Accounts → click on “add another emails address”
On the pop-up window fill in the Name (group name) and email address and tick the checkbox → click on “Next step”
tick checkbox
Click on “send verification” and ask your group admin to verify it!
The shared mailbox appears in your account settings. Below it → click on “Reply from the same address to which the message was sent”
tick this option
In your settings navigate to Labels → scroll down and click “Create new Label”
create new label
Create a new Label named as your Group or Mailbox
In your settings navigate to “Filter and blocked addresses” → Create a new filter
Fill in → TO: “shared email address” → click on “create filter”
Tick the option on the screenshot below and click on “Create filter”
tick options
Now you will find all emails from the shared mailbox under the named Label view!
Label view