I am trying to read the GD&T Symbols like Concentricity, Perpendicularity using ezdxf parser on DXF Files. The GDT Symbols get read as TOLERANCE Entity and using the content attribute I have succeeded to find the tolerance value, GDT Type and the associated Datum. Is there a way I can find out to which measurement (for ex - Linear dimension), it is associated with ? For ex - In the image below, I am able to understand that there is a Concentricity Symbol, with tolerance 0.02 with Datum. I do not know what is the other circle being referred to (Concentricity being a feature dependent on two entities, one is the datum and the other unknown). I would want to know that the Concentricity is associated the the linear dimension phi 13.

You can find the DXF at this location Sample DXF File

Any help would be appreciated.