When you log in to an Immo-Connect application, you will be presented with a screen where you can choose how you want to use the application.
In other words, here you can already choose a certain organisation.
If the required organisation/combination is not in the list, you can create a new combination via the provided button.
If you are already logged in under a certain organisation, click on your name in the top right corner and choose the option to change the context.
You will be taken to the screen above and perform the same action.