Users in Nexonia can be filtered so that they can only see and select custom field values that a Nexonia Administrator allows them to.
To enable filtering of custom field values by user, navigate to: Settings > Company > Custom Fields > Edit the field > change filter by setting to User.
Next, you will need to filter the values of this custom field that the user should have access to. Under: Settings > Users > Users > edit the user > Custom Fields > edit and apply the appropriate custom field values.
Once you've completed the configuration for this user, click Apply at the bottom to save your changes.