Ik ben er inmiddels achter hoe je een groep maakt in Friendica. Even gecopypasted uit het Engels, met dank aan @Erik van Schaaik :

"To create a group like Facebook, you have to make an entirely new account on Friendica, then switch it to a Group account in the settings. You can use the same email address as your personal account".

"In Friendica, you can create sub-accounts under your main account. These can function as groups. By giving your sub-account a clear name, everyone will immediately know what the discussions are about.

SWITCHING BETWEEN ACCOUNTS
If you have one or more sub-accounts, you can easily switch between your main and sub-account:

Click on your avatar in the top right corner.
Select ‘Accounts’ and choose the desired account.

CREATING A SUB-ACCOUNT
Click on your avatar in the top right corner.
Go to ‘Settings’.
In the left menu, click ‘Manage Accounts’.
Click the hyperlink ‘Register an additional account’.
Enter the following details:
- Display Name: a name for the group (for instance: Make Love, Not War).
- Nickname: a unique username (for instance: Lennon@friendica.world).
- Password: enter the password of your main account (no new password required).
- Do you want your main account to also participate in the group? Then choose
‘yes’ under ‘Include your profile in member directory’.

SETTING UP THE SUB-ACCOUNT AS A GROUP
Log in to your new sub-account.
Click on your avatar in the top right corner and go to ‘Settings’.
Click ‘Account’ in the left menu.
Click ‘Advanced account types’.
Choose ‘Community Group’, then ‘Public Group - Restricted (Contact requests have to be manually approved)’. People cannot join the group automatically. When someone requests to join, you will receive a notification with an access request, which you can approve or deny.

ADDITIONAL OPTIONS
There are many more things you can add and settings you can set. Besides setting up a group, you can also configure your sub-account as a regular account or explore other options."