Relationship assignment on contacts with multiple contact subtypes

If there are contacts with multiple contact subtypes assigned and there is defined a relationship between one of this contact subtypes and any other contact, when you try to assign a relationship from the other contact, in the "Select Contact" input form, you can not match these contacts.

I give an example:

Definitions:

• Contact subtypes: 'CS.A' and 'CS.B'
• Contact: 'C.A'
• Relationship: 'R.A'
• Contact 'C.A' is a 'CS.A' contact subtype and a 'CS.B' contact subtype.
• Relationship 'R.A' relates any contact with a 'CS.A' contact subtype.

Problem:
If we try to create a relationship 'R.A' from any contact to 'CS.A' contact, when we want to find this contact in the "Select Contact" input form, it finds nothing.