Hi Ian,
Unfortunately, access to assets is all or nothing. More granular permissions is something which is being looked at but it's also something complex. You can find more information about the permissions within Lansweeper here: https://www.lansweeper.com/knowledgebase/web-console-user-roles/
One option which larger companies sometimes use is to purchase multiple subscriptions, allowing them to have multiple databases to split permissions that way. Obviously, this is not an optimal solution.