How can I remove/hide the project area shown in Restricted Access drop-down list?

Hi everyone,

Is there any way to hide/remove the project area names from Restricted Access attribute?

Since I just want to utilize this attribute with the access groups which are created by myself, I don't need the project area names to be shown in the drop-down list.

Once there are more and more projects to be created, then the options in drop-down list of Restricted Access attribute may be too many to confuse the general users for choosing the exact access group they want.

If there is any way to config this property, please tell me, thanks for any reply and help.