Elements Direct Modeling/Annotation
Often it is necessary due to space problems or for readability dimensioning circular elements on-sided.
It is possible to choose the Sym Single or Sym Long Linear Dimension Styles, though they will leave the line towards the symmetry centre on. It is not possible to switch off this line.
A workaround is to break the line from the arrow until almost the centre for it not to be visible. Although as soon as moving the dimension again or updating the drawing it will jump back to normal.
This is a common way of diameter annotation and it would be good if this was feature.