This functionality may not be available on all pricing plans.
Once you have generate.TAX open, go to the Users tab and click on the 3 dots next to the user you want to change permissions.
Click on Access rights option from the menu.
You can choose the entities for which they should have access and then you can add and remove the specific permissions per entity.
By clicking Apply the changes are saved only to that entity, and when clicking on Apply to All the permissions will be replicated to all entities.
You can Close the tab to automatically save.
If you hover on the question mark (?) next to each permission you get a description for that tag.
You can also check out the following video on how to assign advanced access rights.