When creating a Relation that is to another Object you can limit the selection to a Type. This is a blunt method of filtering.
Add the ability to filter on Object Type and Filter
Add additional filter to the Type once a Limit Object Type has been selected.
Allow filtering by Tag
I have Organisations with tags (Insurer, Passport Issuer, Shop)
I have Documents that have an Issued by relation to Organisations.
I have a Template for Insurance Policy, Passport Office.
The Template should show Organisations where the Tag is relevant to the Template
So Passport document template should limit Issued by to Object Type of Organisation where Tag=“Passport Issuer”
Creating additional Types and using this to filter Type - this is wasteful, I only have two Passport Issuers (for example), I may have three Insurance Companies