Redmine › Extended Fields

I would like to suggest a new feature for the Project Selection Custom Field.

We have projects to store different kinds of information (products/services). I would like to be able to link these services to things. The Project Extended fields allows me to do this but it always shows the whole project tree, which in our case is quite large.

If would be nice if you could configure the custom field to allow the selection of a project from a particular parent project. This would make it easier for the user to select a particular project from a range of projects in a particular area.