With the Snap Line command you can create auxiliary lines which snaps the balloons/dimensions to it.
These lines can be created as a parallel line with the view's edges (Offset View) or with a components contour edge (Offset Object).
If you want to drag the end of the balloon on an edge or surface it can be done if you are under the Table or Annotation tab.
If you want to place onto another edge or surface: select the balloon > right click > Edit attachment.
In the menu you can choose from:
On Entity: place to edge
On Surface: place to surface
Midpoint: midpoint of an edge
Intersected: intersection of two edge
Also you can modify the end of the ballon here (arrow, filled dot, etc.)