Add "strict" option for SearchAPI "User Domain Access" Filter

The SearchAPI Filter "User Domain Access" is implemented as:

User Domain access
Apply User Domain Access to the index. Note: This implementation loosely follows Domain's grant method. This means that users will be visible if they are assigned to the current domain or a domain where the searching user also is assigned to. Further filtering (like current-domain only) should be done with FacetAPI. The searching user must have 'View users profiles' permission.

Can a second option "strict" be added?
This option should:

1. Only give access to users assigned to domains, where the searching users is also assigned to.

Where the current method also gives access to users assigned to the *current* domain.