Once you've set up and added users to Bidrento (which you can read about here), you can also define the buildings to which the user has access to.

If your environment contains multiple buildings, but you don't want a user or multiple users to access the data for all of them, you can change the settings under Manage users here.

By opening up the users list, you can see all of the users you have in your environment. Click on the desired user to open up the user card.
Now you can see the environment name, permitted buildings and role among other things, they're connected to.

Click on the permitted buildings, and a slide-in window appears, where you can see the buildings the user has access to. Select the ones you want the user to have access to, and unselect the ones you don't want the user to have access to. After that click on "Save".